Breeding the family

Back in 2019 my brother died on active service, having married just before his deployment. His now widowed wife asked me to get her pregnant, at first it was to be IVF. But as it dragged out and the start of the pandemic caused it to change. Living in the same apartment building owned by my family, with the lockdown we started sexual intercourse to get her pregnant. The wider family knew of her IVF treatments and once pregnant assume4d she had got pregnant by using IVF. They didn't ask who sperm was used just assuming it was my late brothers. I've since married my girlfriend who was working in the next state during the lockdown. Only me and my sister-in-law know who the actual father of her 2 children is, a son named after my late brother and a daughter born early last year name after her late grandmother. She has told the family she'll no more IVF treatments as 2 is enough. We get on very well, but the sex was for the purpose of her having children nothing else. I was happy to help, and it made my parents happy thinking their deceased son had 2 children.