Chris never stops sending Winona letters and pictures. Never.
Every chance he gets, he's sending packets of information so huge that Jason's and Gary's PADDs can barely handle the load: there's updates and revised allergy information, and photos from school or from aboard the Endeavor; there's photos from a trip to the Mojave and a trip to Vulcan. He writes her letters that he wonders if she even reads, but it makes him feel better to write them so he keeps doing it.
Jim, however, never sends so much as a note.
After all, she'd abandoned him, she'd left him, and she'd never spoke to him, and though Chris suggests Jim send her something, he can't force Jim to do what he does himself.
So Chris continues to send it all, finding time at night when Jim's asleep to compose everything. He tacks on whatever he can that shows how tall the boy is getting, how his hair has turned more and more sandy blond, and how he's bonded with Chris's nieces and nephews to the point that little Grace refuses to accept that there was ever a time Jim wasn't there.
(She reads them all, but ignores the pictures. She doesn't want them or the reminder that she's not there to witness her son growing up in person. The letters, at least, feel like she's reading a book, reading about someone else's life that she's got nothing to do with.
It hurts less that way.
And they're what the guards find open on the little table in her cell the morning after Winona dies, those letters; she dies of an sudden, massive heart attack, but there's a whisper that goes around the colony that it was sadness that killed her in the end.)