Is it disrespectful and rude to ask someone how they got their children?

I was recently trying for a baby with my ex female partner. When we told people we were ttc they would say things like "well how are you doing that" and other very personal questions. Now that I'm single I am starting the process to be a foster parent licensed for children under two as I feel I am able to provide unconditional love to children who need it. I was talking to a single foster mum that also had bio children by choice and people always ask her why she choose to be a single mother and asked hoe she got pregnant etc. That leads me to the question is it rude to ask someone how they got their children?