It was my DD's birthday(7) yesterday and we bought her a doll carriage, one which she had wanted for ages.
My SIL came around with DN's (8 & 3). We were sat having coffee and the girls were playing together, whilst the 3 yo was playing happily by herself. DN then saw the carriage and started playing with it - decided to sit on it and snapped the wheel off.
All my SIL said was oh dear .... 
It was obviously DD got that for her birthday and now she's lost out on a present she really wanted.
Aibu to expect SIL to at least offer to either pay or replace?