Is she a Gold Digger?

MG,

Ok so here is the dilemma, a really good friend of mine asked me what I thought about his situation and I don't really know what to say. Here is the situation; he bought a ring for his girlfriend but while it was getting sized and he was figuring out how he would ask her, something happened. Her sister's boyfriend asked her sister to marry him. So, big deal it doesn't change what my friend wanted to do or how he feels about his girlfriend? Well even if it didn't change somethings the situation as a whole is now very different. Here is just one part, the part I am asking about for now anyway, he is afraid that he needs to change the ring. Well not need so much but... The thing is that he got a really beautiful 2(ct)/E/VVS1 center stone, but her sister's ring is a 2.75(ct) flawless. Not that he thinks his girlfriend won't say yes if the stone isn't big enough but she is the elder sister and the second to get asked, so he just isn't sure what to do. Oh and here is the other part of the conundrum, he found out that the sister kicked in to get a bigger better stone. It's not that he doesn't have the money, 'cause he does. It's just that he thinks, and I agree with him, $20,000 is more than enough to spend on a ring. He also knows that it doesn't really matter but it just seems to in his mind. Actually writing this all down it seems like a silly problem but it still is a problem at least in his mind and I am not sure what to say. Help please.

Dear Whatever Your Name Is,

His girlfriend will not even be thinking about the size or whether or not it's bigger than her sister's. Unless, of course, she's a superficial, gold-digging whore. As long as she is none of those things, he has no worries. All she will be thinking about is the happiness and excitement of marrying the man she loves. Trust me. Besides, it has always been my belief that a wedding ring can change through the years---you can add diamonds to it for representation of the children you've beared, etc.

XO,
MG