At a wedding today, there was a bouncy castle and some boys of about 5/6 told my DD to get off because she's a baby. She told them she wasn't going anywhere and that she's nearly 4, not a baby. She has speech delay and a speech impediment and the boys howled with laughter and told her she speaks like a 'stupid idiot baby' and that the castle was for big boys like them. DD was on the verge of tears so I went over and said that if they were such big boys they would know not to be so rude and unkind to others. One of their mums overheard and came over to glare at me but didn't reprimand her son. I told DD to carry on bouncing and the boys scurried off. WIBU?