Harry James Potter was born on July 31, 1980. Or at least, he would've been. Instead, the midwife was shocked to discover that the baby of James and Lily Potter was a young girl. Since the two adults had figured that the child would be a boy, they had decided only on the name Harry James Potter. In a dash to figure out a name, James suggested Harriet, which of course, Lily turned down. (Because she had some sense in her and didn't want her daughter to be named Harriet and also give James an easy way out and be lazy.) Lily did like keeping the H though. After opening a latin book and quickly skimming through to find a suitable name that had a ring, little Hadria Rose Potter was named.
Baby Hadria had an a fun time and enjoyed her bi-monthly visits from Uncle Padfoot and Uncle Moony. The Fidelius Charm gave them protection, but it was safer to have less people entering and exiting, so visits were made only occasionally, unless of an emergency. Wormtail had only came by twice after becoming Secret Keeper, which the Potters assumed was due to hiding out to not reveal their location. Instead, Peter Pettigrew was doing the exact opposite.
The Death Eaters arrived one day and threatened to torture and kill him if he would not give away the location of the Potters. They kept coming back and he shortly broke. He was Marked and revealed his friends' location to the Dark Lord. He later thought he made the wrong decision, but fear makes you do strange things.
And so, on the night of Halloween in 1981, Hadria became an orphan and the wizarding world celebrated the great Hadria Potter, the Girl-Who-Lived's defeat of the Dark Lord Voldemort. Dumbledore gave Hagrid orders to take little Hadria to the Dursleys as they were her only living relatives. Mourning the deaths of his best friends and not thinking clearly, Sirius Black was later arrested and brought to Azkaban.
Life at the Dursleys' was less than okay for Hadria, but it could've been worse. Her aunt and uncle kept her locked in a cupboard under the stairs and forced her to do a bunch of chores around the house, saying she had to earn her keep. Her cousin though, took somewhat of a liking to her. He had always wanted a sister deep down and decided he would find one in Hadria. The two grew up close, but the adults would separate them, trying to keep their precious Dudley untainted. This meant they couldn't get really close and know one another, but they did like the other and tried to help them when they can behind the adults' backs. Dudley would sometimes sneak her some food while she was locked in her cupboard for long periods of time and Hadria would try to help him on his schoolwork when the adults were gone.
Time passed by, and Hadria found herself face-to-face with a giant man, who had just knocked down the door.