If it really doesn't sit well with youto leave her, then don't. Gotta go with your gut instinct.
In saying that, she probably would be fine, expecially if it is during a time that she doesn't need a sleep. Then they can just have a nice cuddle together, or go for a walk or something. have you thought of taking her with you, but taking Grandma aswell? THen Grandma can care for her, but you wil lbe there too