She is only in reception. They were at a party and spinning around in their party dresses and another child told her she "looks fat when she does a twirl". She has a pot belly on her but she is actually tall and slim and long limbed apart from that. The other child is six months older and the youngest of four with older sisters. Should I be mentioning it to the mother? I see a lot of the mother as my daughter and hers are 'best friends'. She's quite approachable but my husband doesn't think I should mention it. WWYD?