Hubbys mom already competing for "grandma dominance"

But she is driving me absolutely insane since I've gotten pregnant. She acts like she needs to compete with my mom, and since her daughter has had a kid, she's already got "grandma cred" whereas my mom hasn't been there done that yet, and it's turned into a few passive aggressive Facebook comment conversations already. My mom is trying to give her the benefit of the doubt and say that she's just very excited, which, yeah is true, but my mother and I are very close, and I don't appreciate the weird competitive vibes. I don't know if she's just overcompensating because she's scared she's not going to get as much time with my baby as she did with her daughter's (the kid is 7 and they still live with her...so yeah you're obviously not getting that kind of face time with my child) but I feel like it's pretty normal, unless you have a bad relationship, to spend more time with your own mom than someone else's. It just makes me want to spend less time around her honestly because it feels so petty. Every time she talks to my mom she puts the emphasis on saying "I'm so excited about MY baby" or "that's gramma's girl" like can this not be about you please? It's my baby, she's my girl, she will spend the most time with who I spend the most time with, and that is just how it works. It's not like I'm going to purposely exclude her, but the fact is that my mom and I are practically best friends, and she is, with the exception of my husband, the person I spend the most time with. So it's a little hurtful to me that my mother in law whose daughter and granddaughter still live with her, is being so negative toward my mom for what I assume anyway, is jealousy over her being the more present grandparent--especially since she is that grandparent in another child's life! I really love her, truly. But my mom is my mom. She wins. And she deserves to have the time with my daughter without being bullied for it. Like ladies you're menopausal surely we can grow up..? It's just so frustrating and I know it's going to cause an argument between my husband and I somewhere down the road, it would be nice if there were just a way to nip it in the bud now before she even gets here to avoid the negativity altogether. 

Anybody else dealing with similar circumstances?