20mo DD is going to stay with BIL and SIL next week for a few days, and MIL is now really upset because we haven't asked her to look after DD. The problem is that MIL is just not up to looking after an active toddler, physically and mentally/emotionally. We thought she realised this, as whenever she is around DD she's very hands off, even though we always make it clear that she's welcome to do what she'd like i.e. nappy changes, sitting with her while she eats, staying for bath time etc. But apparently not.
DP has a tense relationship with her anyway, though not to the extent that he/we want to remotely limit her interaction with DD, so he's now frustrated by her being upset (which yes, I know is not ideal). DD staying with SIL, who lives ten minutes away from MIL, was the compromise as she's more than capable of looking after an active toddler.
I don't really know what to do. I don't imagine there's a nice way of saying 'you're not capable of looking after a toddler' without offending her even more? 