Gonna sound crazy but please be nice this is already hard enough for me to think about for the future.

SO & I have been ttc for almost 2 years we talked about the future on if I can't carry kids myself who we should get to carry our child. I only know one person which is my half brothers ex gf she has my nieces and nephews. I've been knowing her since I was 12 now I'm 19 almost 20 in July. I'm not sure if she'll help us out though. I know she loves us and also tells us when we are going to give her a niece or nephew. It sucks because she didn't know how long we were trying to have one. She told me it took her 4 years that she was going through her hoe stage and never used protection (shes been tested and shes clean) and she never got pregnant. Till she met my half brother then poof she was pregnant. She had complications with both my nieces from my half brother. She said it was from her family DNA but I'm not sure. Well what my question is if we use my eggs and SO sperm will the baby have complications or no since it's our DNA and not hers she'll just be carrying it.