It's probably not personal although it feels that way. There's a lot of trauma that comes with fertility issues. She's looking to bond over that shared experience. If she's resentful then you don't need that energy in your life anyway
If they are asking the question they should be able to handle the answer. As someone who struggled for 10 years with infertility I know that it is a hard road but you can't fault someone else for something you have gone through. We are all different.