Emotional

Im feeling a bit emotional today, and I'm hoping there's nothing wrong with it. God took my little girl back in July when she was just a few months over 3 (her 4th birthday is next month) and we found out I was pregnant a week before she passed away. My sister found out when I was about 13 weeks pregnant that she was pregnant as well, which we were all surprised about because she was just talking about how she didn't want another baby. Today they found out they're having a little girl, while I'm having a little boy I didn't use any part of her name, and she asked me if it was alright if they used her first name as their daughters middle name. I told them it would be okay, but I'm feeling pretty upset and sad about it all.. I'm so happy for them, and I think it's wonderful they want to use her name in their daughters name, but is it wrong for it to hurt?