My mom seems disengaged from her baby grandson

Help me understand why my mom seems so detached from my 6-month-old nephew. When my sister-in-law announced her pregnancy, the first thing my mom said was to not expect her to help. She didn’t even try to fake being excited. My mom later apologized, but it was a disappointing reaction.

I’ve read that sometimes the sentiment changes once the baby is born, but my mom still seems very disengaged from her grandson. She hasn’t held or physically touched the baby a single time. After several family get-togethers, I have seen my mom only on two occasions wave to the baby and smile at him from across the room.

I feel an abundance of love for my nephew: I love holding him, playing little games that make him giggle, and buying him baby gifts. I’ve babysat him alone several times, and I am happy to help as much as I can outside of my full-time job. It’s hard for me to understand how my mom can be so emotionally and physically distant.

To her credit, my mom has engaged in her own way, like buying tickets for us to all go to the zoo. My mom never has been an affectionate person (didn’t even give us hugs growing up), so part of me is wondering if I’m just seeing her more clearly.

I’m grateful that in my own life, my brother and I have learned the importance of physical and emotional affection: we both have very loving partners and friends. But I can’t help but wonder if my mom resents any extra “responsibility” and/or feels like being a grandma means she’s entering a later stage of life that she’s not ready to accept.

Please help me understand my mom better! Any advice on how to best navigate?