I know it's another Mil moan, sorry - but for heavens sake, DD2 is 20months, and DD1 is 3.5.
I was away yesterday and DP went to pick them up from his parents, who had been looking after them. The kids usually have tea there before coming home, and MIL gets them changed into their pyjamas for the car journey home, as they fall asleep there, and then by the time they get in, it's straight to bed.
So coming home today I find DD1's age 3-4 pj's strewn in DD2's cot. DP said that was indeed what she came home in. DD1 has also, at other times, been dressed in her pj's to go out, and put in daywear for sleeping in. Basically I'm thinking of putting labels on everything, but is that petty?