Alone for 24 hours is not acceptable in my opinion.

I think that is great that you are going to check in our
her dog and "let him in at night"?

(now my gates are always locked, my dogs are large
and I doubt they would allow someone to steal them.)

When I go on short vacations, my Aunt checks in on my dogs
3 times a day. (she feeds them breakfast and dinner
and lets them inside the house for bedtime and I still
worry about them. )