RedFocus - how old is your daughter? Of course she wants to look grown up - all little girls do. There is a fine line between looking tarty and grown up. I'm sure your beautiful daughter did look gorgeous in her dress. 'Grown up' in one person's eyes is 'tartiness' in another's, so it is actually not an awful thing to say - simply a point of view.
My son does Motocross, which is a very male-oriented sport (some girls do it, but it is mainly the blokes). A lot of the girls hang around (some of them very young) dressed, IMO, very provocatively, encouraged by their parents. I think this is wrong, personally. I want to sweep those little girls away and make cakes with them, and tell their stupid mothers who are allowing them to dress like that to go and do one.
Fashion companies manufacture clothes that they think parents will allow the kids to buy - which of course they do, because they are easily taken in. So quoting "Newlook's 915 Range" as being acceptable is actually not, because "Newlook" are simply catering for the gullible market.