I would be concerned if it caused bad feelings between your mum and your baby. If you love it, then use it. Your mum will get used to it. Maybe use it as a middle name if you think it's going to cause huge issues. Would your mum be upset that you're used your grandmothers name and not her name?? Some people see it as how much you love them, not how much you love the name KWIM. My dad got so offended when I said I wasn't going to use any of his names if we had a boy, but we were going to use Shel's biological dads name, and he was so offended that we valued Shel's bio-dad more than him. Yes, that is the case, but not the reason. We just like the name we wanted to use!