Your Mom is probably right. I was in a wedding this past weekend and there were 5 bridesmaids including myself. 2 of them were very tall like 5'6" or taller and extremely thin and 2 of us were short 5'3" or shorter and about average weight and another was a in between height wise and is what I call spoon shaped (her weight resides in her hips, butt, and thighs). The fact is that all of us wish we looked like the other ones. The thin one's were jealous of our breast and how full we looked in the dresses - while the average one was jealous of their height and tummy and we all agreed that we wish we had more curves like the 5th girl. And she wished that she didn't have them! We all just laughed because none of us were really happy with the way we looked - even though we all looked great!
We are constantly plagued by what seems to be perfect women - they are everywhere in magazines, billboards, and commercials. The problem is they are not real women! No real women looks like that without professional help! I use to work for an advertising agency and graphic designers can do amazing things with computers - I've seen it! That is why I like Tyra Banks and Jenny McCarthney because when they go on talk shows they will actually point out what was covered up and changed on their body.
Not to mention sizes are so off - do not pay attention to the sizes of anything! I went to kohls and bought 2 pair of size 12 pants and they fit great! I have a pair of size 12 pants at home though that I can only wear on "skinny" days. My advice - ignore the sizes and concentrate on how you look and feel in the clothes that you buy. No one needs to know that you bought an X-large shirt!
~Amanda