How anal should I be with instructions for MIL (who is watching them)?
She is around them at least once a week. She has watched DD2 alone once a week for the last 2 months (1.5 hours).
It isn't DD1 I am worried about, it is DD2. She is still BF has a pretty specific bedtime/nap routine and still wakes at night to nurse. My big thing is that DD2 gets diarehea when she is given CRAP to eat. MIL is notorious for giving them suckers, licorice, chips, chocolate milk, etc. I just hate that I am going to have to deal with the 'rehea for days afterwards.
Re: First weekend away - a few ??'s
I would write a pretty specific schedule for both girls explaining they do best when we do "XYZ."
We did this when my parents watched DS for a long weekend. When I was talking with my Mom/Dad I tried to be a gentle as possible with our suggestions but also I uderstoond they will still do things their way to some extent. I know my parent's coddled DS a bit more at night then we usually do (ie: picking him up at night insteat of shooshing/patting his bottom) but there wasn't too much re-programming we needed to do when we got home. re: your older daughter, perhaps you can suggest other 'treats' than the ones that upset her tummy and let your MIL pick up her choice in those (that way she kind of owns the treat).
I can completely realte though, my MIL had a big plate of cookies on her table the other day when we went for lunch. DS saw them and wanted NOTHING to do with his lunch after that moment. Ugh!
Side note: Have a fabulous time away!