MIL obviously favoring grandchildren

Anyone been in this situation? My MIL has 2 granddaughters. Our daughter and her daughter’s daughter. Granddaughters are 2 and 3 yrs old. We live a few hours away, but her other granddaughter went from living in my MILs home to moving across the country. She obviously misses her other granddaughter a ton of course and I understand they’d have a really strong bond living together awhile. My MIL was like her second mom. Her parents aren’t very stable so I think that also makes my MIL feel a stronger attachment to her

Anyway we make sure we visit MIL every other month or so. 2 weeks ago we were there. My husband recently pointed it out that MIL makes it so obvious she favors her other granddaughter. My initial reaction was it makes sense bc they did live together. But then I started paying attention and now it’s really frustrating me. She does make it seem obvious.

Whenever we visit, she is literally on her phone the entire time. It’s really almost nonstop. She really barely interacts with her. I have noticed this all my daughters life besides when she was a newborn, but I didn’t really notice how little she really does interact with her up until recently.

My daughter is speech delayed and she was talking really good doing abcs and my husband and I were all excited cheering her on after and my daughter was so cute giggling bc she was proud of herself. My daughter smiles at my MIL hoping for a reaction I could tell. I glance over at my MIL and she’s just serious staring at her phone. She’s in her 40s too so he’s not like she’s just older and oblivious. And I don’t expect her to pay constant attention to her or anything but the lack of interaction when she doesn’t get to see her often makes me so sad and even when she’s obviously doing something cute she doesn’t even look. And it wasn’t a one time thing like that, it was like that the whole time. She probably spent 5 mins (if that) in all interacting with my daughter that whole week we visited. Probably less. I just know if her other granddaughter was there she would be interacting more and paying more attention. I don’t know if the lack of interaction has gotten less recently or if it was always this bad. I can’t believe I didn’t notice it so much until my husband said it tho

MIL texts me all the time about her other granddaughter which never bothered me but now I find myself feeling slightly resentful. She was saying she was video calling and granddaughter kept signing all these words and she was so impressed. Usually I’d find that so cute, and I still do, but I’m like why weren’t you paying attention to our daughter when we visited in the same way? Is she telling anyone else the cute stuff my daughter did? She was signing a bunch of things too and doing all these cute things too and I don’t even think she noticed

Just another little example, she buys both girls the same toy but had to get dif colors. Both girls have the same fav color, pink, but she gives the pink one to the other granddaughter. I’m grateful she buys toys and I know that’s really a little thing but it’s all those little things that add up that bother me. There’s a lot more examples like that

Also MIL has always made it obvious she has fav pets. When I first met her, I remember finding it weird I could tell which dog was her fav by how she treated her.

Am I overreacting? Anyone else had a grandparent obviously choose favorites? And it’s not like MILs just quiet, she talks a ton to my husband and I. I’m not usually jealous like this but the treatment just doesn’t feel right