Need quick advice for some friends pls!! ?

I have two friends who are sisters, twins. Identical. Sally & Sandra. Sandra is getting a tad worked up thinking she is ugly - when she clearly isn't. As people are always always saying how strikingly beauitful she is. No one has ever called her ugly. Now this is because, whenever Sally goes out, girls who are jealous of her (some of them she knows, others she's never met nor heard but they know people she knows and even complete strangers) will cause a fight with her because they are jealous of how she looks and they feel threatened (they later admit it) Sandra was saying to me earlier why does that never happen to her? She always gets the odd person saying she's gorgeous, but never gets them going to the trouble of hitting her or mouthing off. Now that used to happen when she was at college. I told her its probably because, girls can sense that she won't take it and would fight back, and her sister Sally is probably more of a target. Now what do you guys think! Cos she's not ugly, but thinks she is. Because girls don't get volient to her but just her sister! She's making me so mad!