How many rishta’s have you turned down?
I don’t think it is fair for someone to look down on someone who is just an undergraduate or who hasn’t been to a top university. Did you go to go to Oxford or Cambridge btw? I agree with Sara516. I went to a top uni’ myself and have never cared if so-so has even an ex-polytechnic degree.
Regarding looks - well I think your sister is right. We need to look at ourselves properly. 
Also, what if that successful, good looking guy’s luck changes one day?! Or after marriage he loses his job because of his temper, just wears sweaty t-shirts, smells, farts in bed all day and becomes a lazy couch potato?
Don’t put looks on top of your list because its not as important.
A love forged in flames: The awe-inspiring story of how a badly-burned soldier married his sweetheart | Mail Online