Help!! Baby spit up question

Lindsay

My daughter was born on 2/17. She has been spitting up after almost every feeding whether it’s been breast milk or formula. She has gained weight and burps almost every time. Is having regular wet and poopy diapers. I’m not sure how to get her spit up to slow down?? It’s more then just a little bit it’s not full on vomit. I sit her up for about 10-15 minutes after feeding her. Advice please??