I am in the same boat as you with working full time. I am also a grandmother for the first time
Oh what a joy! I spend my day off adoring my sweet grandchild, and helping the new parents out.
I have made 2 baby quilts and one guild challenge lap size quilt this year. I have made many masks for friends and family. I am also enjoying my other hobby...knitting, as it allows me to take it with me on the patio when the weather is nice...or while my grandchild sleeps, I can knit a bit.