Thanks to you all. I will definitely keep talking to her about it - Kerry, love the story of your dd standing up to the mean kid, fantastic

Nautigal - thanks for the tip on the article. I read other things along the lines of what you were saying and know what you mean. Dd is really good socially these days. She gets along really well with other kids and once she's warmed up, she is often the leader of a group. What does pose a problem for her is that she is very aware of being judged by other kids (who in reality, at least with regard to her age peers, are not yet capable of a judging her in the sense that she understands it). For example at 3 she refused to ware a jacket I had bought her because it was unusual and she felt "the other kids will think I'm weird" (when in reality I doubt they'd notice a jacket unless it had Dora the Explorer or some other character on it!) Similarly, a few months ago when the parents of one of her friends called to say their daughter couldn't make a play date because she was sick, dd said "I don't think x is sick, I think she just doesn't want to play with me" - again, I am pretty sure most 4 your olds have not yet grasped that that is even an option (consciously at least, though appreciate that some might actually 'feel sick' if they don't want to do something or feel anxious about it). Certainly it isn't an excuse we've made on dd's behalf, so where she's picked that up from I have no idea!
While I don't know for sure, my gut feeling from her responses to people being mean or not playing 'by the rules' is that she feels it's because they don't like her or she that she's the one doing something wrong (which undoubtedly will be the case from time to time, but at this stage probably less often than not). Perhaps it's a bit of early onset 'impostor syndrome'! Sigh.