Warning: Spoilers ahead, this appendix is accurate as of the end of the book, so if you skipped ahead to read this... Well you've been warned.
So the formatting on AO3 didn't turn out as well as I anticipated, so I said fuck it, I'll post this here too, because why not?
The appendix isn't as thorough as the ones of the main books, with no household details, and instead it just lists family members, their birth years, their marital/betrothal status, and that's about it.
So enjoy I guess. Below the nine major great houses are listed, but other houses have details as well through intermarriages.
House Stark
{Lord Rickard Stark} (born 242) m. {Lady Lyarra Stark}
- {Brandon Stark} (born 262)
- {Lord Eddard Stark} (born 263) m. Lady Catelyn Tully
Lord Robb Stark (born 283) m. Princess Myrcella Baratheon
- Eddard Stark (born 299)
Sansa Stark (born 286) b. Tyrek Lannister
Arya Stark (born 288)
Bran Stark (born 290)
Rickon Stark (born 294) b. Ryella Frey
Jon Snow (born 283)
Jeyne Snow (born 283) m. Brynden Blackwood
- {Lyanna Stark} (born 266)
- Benjen Stark (born 269)
{Rogar Stark} (born 245) m. {Jena Bolton}
- Torrhen Stark (born 265) m. Tyta Frey
Edwyn Stark (born 288)
Bella Stark (born 291)
- Arrana Stark (born 269) m. Alekeyne Florent
Ser Arryk Florent (born 282) m. Desmera Redwyne
House Lannister
Lord Tywin Lannister (born 242) m. {Lady Joanna Lannsiter}
- Queen Cersei Lannister (born 266) m. King Robert Baratheon
Princess Myrcella Baratheon (born 284) m. Robb Stark
Eddard Stark (born 299)
Prince Joffrey Baratheon (born 286)
Princess Marla Baratheon (born 287) m. Edric Arryn
Prince Tommen Baratheon (born 290)
Princess Lanna Baratheon (born 292)
Prince Loren Baratheon (born 296)
- Ser Jaime Lannister (born 266)
- Tyrion Lannister (born 273)
Ser Kevan Lannister (born 244) m. Dorna Swyft
- Lancel Lannister (born 283)
- Willem Lannister (born 287)
- Martyn Lannister (born 287)
- Janei Lannister (born 296)
Genna Lannister (born 245) m. Ser Emmon Frey
- Ser Cleos Frey (born 264) m. Jeyne Darry
Tywin Frey (born 285)
Willem Frey (born 287)
- Ser Lyonel Frey (born 273)
- Tion Frey (born 284)
- Walder Frey (born 287)
Ser Tygett Lannister (born 250) m. Darlessa Marbrand
- Leila Lannister (born 282) b. Merlon Crakehall
- Tyrek Lannister (born 286) b. Sansa Stark
Lady Margot Lannister (born 253) m. {Lord Titus Peake}
- {Ser Tywald Peake} (born 274)
- Ser Gerold Peake (born 279)
- Lenora Peake (born 286)
{Ser Gerion Lannister} (born 255)
- Joy Hill (born 288)
House Tyrell
Lord Mace Tyrell (born 256) m. Lady Alerie Hightower
- Willas Tyrell (born 272) m. Floris Baratheon
Alester Tyrell (born 290)
Royce Tyrell (born 292)
Elaena Tyrell (born 295)
Harwin Tyrell (born 298)
- Ser Garlan Tyrell (born 277) m. Leonette Fossoway
- Ser Loras Tyrell (born 281)
- Queen Margaery Tyrell (born 283) m. King Renly Baratheon
- Tyanna Tyrell (born 285)
Lady Mina Tyrell (born 257) m. Lord Paxter Redwyne
- Ser Horas Redwyne (born 274)
- Ser Hobber Redwyne (born 274) m. Asha Greyjoy
Maegelle Redwyne (born 293)
Lythene Redwyne (born 294)
Alyx Redwyne (born 297)
- Elinor Redwyne (born 278) m. Lord Elwood Meadows
Ryam Meadows (born 295)
Patricia Meadows (born 297)
- Ryella Redwyne (born 280) m. Lord Tommen Costayne
Gilbert Costayne (born 298)
- Desmera Redwyne (born 283) m. Ser Arryk Florent
Janna Tyrell (born 260) m. Ser Jon Fossoway
- Ser Meryn Fossoway (born 277) m. Meredyth Crane
Mychael Fossoway (born 297)
- Ser Raymun Fossoway (born 278) b. Serra Frey
House Baratheon
{King Robert Baratheon} (born 262) m. Queen Cersei Lannister
- Princess Myrcella Baratheon (born 284) m. Lord Robb Stark
Eddard Stark (born 299)
- Prince Joffrey Baratheon (born 286)
- Princess Marla Baratheon (born 287) m. Edric Arryn
- Prince Tommen Baratheon (born 290)
- Princess Lanna Baratheon (born 292)
- Prince Loren Baratheon (born 296)
His Acknowledged Bastards:
Mya Stone m. Ser Mychael Redfort
{Ser Orys Stone} (born 281)
Rhaelle Stone (born 282) m. Harry Hardyng
{Ellyn Storm} (born 283)
Bethany Storm (born 284)
Sarra Waters (born 285)
Edric Storm (born 287)
Torwyn Pyke (born 290)
Jonnel Hill (born 291)
Clarent Hill (born 292)
Steffon Rivers (born 294)
Prince Glendon Martell (Born 295)
Lyanna Rivers (born 296)
Lord Stannis Baratheon (born 264) m. Lady Jacaera Velaryon
- Ser Lyonel Baratheon (born 281) m. {Laena Celtigar}
Mariah Baratheon (born 297)
- Ser Ormund Baratheon (born 282) m. Betha Swann
- Alaric Baratheon (born 283) m. Myrielle Penrose
- Ronnal Baratheon (born 284) b. Talla Tarly
- Shireen Baratheon (born 289)
Floris Baratheon (born 274) m. Willas Tyrell
- Alester Tyrell (born 290)
- Elaena Tyrell (born 292)
- Royce Tyrell (born 295)
- Harwin Tyrell (born 298)
King Renly Baratheon (born 277) m. Queen Margaery Tyrell
House Greyjoy
Lord Balon Greyjoy (born 255) m. Lady Annalys Harlaw
- Rodrik Greyjoy (born 272)
- Elenei Greyjoy (born 273)
Torwyn Pyke (born 290)
- Maron Greyjoy (born 274)
- Asha Greyjoy (born 276) m. Ser Hobber Redwyne
Maegelle Redwyne (born 293)
Lythene Redwyne (born 294)
Alyx Redwyne (born 297)
- Theon Greyjoy (born 278) m. Princess Rhaenys Targaryen
Casella Greyjoy (born 294)
Goren Greyjoy (born 298)
Euron Greyjoy (born 262)
Victarion Greyjoy (born 264)
Aeron Greyjoy (born 270)
House Arryn
{Lord Jon Arryn} (born 218) m. {Lady Jeyne Royce}, {Lady Rowena Arryn}, Lady Lysa Tully
- Lady Sharra Arryn (born 254) m. Lord Yohn Royce
Ser Andar Royce (born 273) m. Wylla Corbray
Perra Royce (born 294)
Ryella Royce (born 275) m. Ser Arwood Frey
Ryella Frey (born 294) b. Rickon Stark
Androw Frey (born 296)
Alyn Frey (born 296)
Ser Robar Royce (born 277)
{Ser Waymar Royce} (born 278)
Ysilla Royce (born 280) m. Domeric Bolton
Princess Rhea Royce (born 282) m. Prince Daemon Targaryen
Jeyne Royce (born 282)
- Lord Edric Arryn (born 285) m. Princess Marla Baratheon
- Alyssa Arryn (born 289)
- Robert Arryn (born 292)
House Targaryen
{King Aerys II Targaryen} (born 244) m. {Queen Rhaella Targaryen}
- {Prince Rhaegar Targaryen} (born 259) m. Princess Elia Martell
Princess Rhaenys Targaryen (born 279) m. Theon Greyjoy
Casella Greyjoy (born 294)
Goren Greyjoy (born 298)
King Aegon VI Targaryen (born 281)
Prince Daemon Targaryen (born 281) m. Rhea Royce
- {Princess Viserra Targaryen} (born 262)
- {Prince Laenor Targaryen} (born 264)
- {Princess Shaena Targaryen} (born 267)
- {Prince Daeron Targaryen} (born 269)
- {Prince Aegon Targaryen} (born 272)
- {Prince Jaehaerys Targaryen} (born 274)
- King Viserys III Targaryen (born 276) m. Elissa Antaryon
Prince Maelor Targaryen (born 297)
- Princess Daenerys Targaryen (born 284) b. Prince Quentyn Martell
House Martell
Prince Doran Martell (born 247) m. Mellario
- Princess Arianne Martell (born 277) m. Ser Andrey Dalt
Prince Glendon Martell (born 295)
Princess Coryanne Martell (born 296)
- Prince Quentyn Martell (born 281) b. Princess Daenerys Targaryen
- Prince Trystane Martell (born 285)
Princess Elia Martell (born 256) m. {Prince Rhaegar Targaryen}
Prince Oberyn Martell (born 257)
- Obara Sand (born 272)
- Nymeria Sand (born 274)
- Tyene Sand (born 277)
- Sarella Sand (born 280)
- Elia Sand (born 285)
- Obella Sand (born 288)
- Dorea Sand (born 292)
- Loreza Sand (born 293)
House Tully
{Lord Hoster Tully} (born 240) m. {Lady Minisa Whent}
- {Norbert Tully} (born 260)
- {Trystane Tully} (born 263)
- Lady Catelyn Tully (born 264) m. {Lord Eddard Stark}
Lord Robb Stark (born 283) m. Princess Myrcella Baratheon
Eddard Stark (born 299)
Sansa Stark (born 286) b. Tyrek Lannister
Arya Stark (born 288)
Bran Stark (born 290)
Rickon Stark (born 294) b. Ryella Frey
- Lady Lysa Tully (born 266) m. {Lord Jon Arryn}
Lady Minisa Baelish (born 281) m. Lord Walder Frey
Ellyn Frey (born 297)
Lord Edric Arryn (born 285) m. Princess Marla Baratheon
Alyssa Arryn (born 289)
Robert Arryn (born 292)
- Lady Wylla Tully (born 267) m. Lord Tytos Brax
Axell Brax (born 288)
Oswell Brax (born 290)
- Marrisa Tully (born 270) m. Ser Ronald Vance
Helena Vance (born 288)
Robert Vance (born 289)
Hothar Vance (born 293)
Walda Vance (born 295)
- Lord Edmure Tully (born 272) m. Lady Walda Frey
- Ser Elmar Tully (born 275) m. Lianne Vance
Elston Tully (born 298)
Ser Brynden Tully (born 245) m. Lady Falia Vance
- Ser Jasper Tully (born 280) b. Samantha Rowan