..I'm very upset

My sister much older than I am, she has two sons that our mother adores. I'm little over 9 weeks pregnant and I was excited to be having the next grandbaby, my first child. I have three sisters so my mother was so excited to have grandsons. My fiancé and I want a girl and my mom wants us to as well. Well we found out my sister is pregnant again and I know her being pregnant is going to push our child out of my mothers "spotlight"... I'm just upset and worried that my child won't get the attention the others have and will. Or as dumb as it sounds I'm worried she'll have a girl and we won't and that'll make our child less important to my mother. How my mom is this isn't as crazy as it might sound..