MIL & baby shower.

My husband had a baby with his girlfriend three years ago. His ex's family was all mad and didn't help her any, so my husband's mom completely threw the baby shower for her. She also bought them a bunch of stuff plus the big items like a crib, car seat, etc. My mom threw my shower and she didn't offer to help at all. But then MIL didn't buy us ANYTHING. No presents. Not even some outfits. Most grandmas would be excited and buy lots of stuff. But nothing. She gave us a card with $100. And it's not a money issue, she actually got a better job in the last year vs. the one she had before. It's like favoritism or something. She's the same way with my husband and his sister. Spoils the sister, does nothing for my husband. Am I overreacting? I feel like she's treating my baby differently.