My husband and I will be going on vacation soon and my parents are coming down to our house to keep our 18 month old while we're gone. My dad will be here with us for two days before we leave so she can get comfortable with him (she knows him but they live a plane ride away so don't see each other often.) This should also give him a chance to get used to her likes/dislikes, hopefully better understand her words, and get used to her schedule. The below are the things I've done so far to prepare:

Told school what days my parents will be picking up/dropping off
Leaving doctor's number and my insurance and prescription cards for them
Written down her schedule
Made a list of fun activities they can do on the weekend
Made a list of favorite foods and stocked them in the house
Wrote down all the details of day care drop off/pick up
Laid out clothes for the day that my dad will be alone with her (mom arrives the day after we leave and she can pick out clothes).
Left instructions for medicine

Any other tips? I totally trust my parents and I don't want to (or feel the need to) be overbearing and tell them things like "don't leave her unattended in the tub". Just want to make sure they feel prepared and comfortable so they can have fun with LO and not be stressed!