Gender change Harry is Harriet.
The prophecy is not about a boy but a child.
Lily and Severus reconciled before the war, Snape let go of Lily
On October 31, 1981, Voldemort led his men to attack the home of Potter and Longbottom. The Longbottoms died on the spot, but their only son Neville survived. Voldemort's spell was reflected on himself, leaving only a lightning-shaped scar on the child's forehead. At the same time, Peter Pettigrew led Bellatrix Lestrange and others to raid Godric Valley, but did not find their daughter Harriet. The Potters were tortured crazy by the furious Bellatrix using the Cruciatus Curse.
After Voldemort disappeared, Bellatrix and others were arrested, and Peter Pettigrew was at large.
The war ended suddenly, and by the time Sirius brought Harriet from Potter's old home to St. Mungo's, the Potters had already been transferred to the Cursed Injury Unit.
According to Lily Potter's previous will, if anything happened to the couple, their daughter Harriet would be raised by Severus Snape, the notorious Death Eater. Harriet's godfather, Sirius Black, expressed doubts about the authenticity of the will and caused a scene at the Ministry of Magic's Children's Protection Society. Snape, who had just escaped prison due to Dumbledore's testimony, did not attend the custody battle. The Ministry of Magic finally ruled that Sirius would be Harriet's caregiver, and Snape would be Lily's designated caregiver and would visit Harriet at least 1 to 3 times a month.