This week we were at the public library. When we arrived there was a mother and her 3 kids (say 8, 6 & 3 ish). DD chose her books and afterwards went over to the little toy box they have there. She picked up a toy and began to play with it. The 3 year old flew over from across the room screaming at her that it was 'mine', trying to tug it out of DDs hands. The mother slightly lifts her head from the half asleep position she's in on the chair nearby.

DD replies with 'no, it belongs to the library and everyone can play with it'. The kid doesn't let up. The mother says kids name 2 or 3 times in a monotone voice. Kid continues screaming at DD for about a minute. At which point I explain to DD that we will just go and play in the garden instead. I had no idea how to handle this situation! I wanted to say to the mother to come and get her freakin kid, I wanted to tell the kid that 'hey, hang on a minute it isn't yours and DD had it first'. Anyway we left, DD asking me 'are they everyones toys to play with?' 'am I still allowed to play with them?' etc. Then within 5 minutes they were out in the garden after us

Tell me, how would you handle that??