Leaving your kid with anyone

On the 18th I’m going on vacation with my 11 month old a bunch of family for 5 days. We are going to a resort. Now I plan on spending my time with my child and enjoying a different state. The problem is the other people that are going seem to think that at night I should just leave my daughter with this old lady who coming. I’ve meet this lady maybe 3 times she is fragile, can barely walk, has lots of health issues. This lady is also supposed to be also watching the other children at night. So how can this lady that can barely care for herself watch about 6 kids aged 4-6 and two infants. Nah I’m like no I don’t feel comfy with that I’m totally fine spending my time my daughter. My whole point of going was to be with my daughter. Especially since I’ll be going back to work full time next month. I don’t understand how people can think that leaving kids with this women is ok, yes in a way she family she married into the family but idk her and she herself needs help with basic life task. Just people want to party so bad that they will leave they kids with anyone. I plan to have fun with my baby and when she go down at night I plan on sitting on my room patio have some wine, sit in the deep tub and I’ll be happy. Why take her on vacation with me if I’m just leave her with someone. If I wanted an adult vacation I would have taken one and left her with her dad or grandma. Not bring her just to leave her with a old lady who can’t even care for herself.