That takes a bit of work, since the context is that she's expected to marry a man, but she's not expected to marry someone of any particular race. However, in cultures where you have an expectation to marry within your race, it'd be fair. I come from one of these cultures, and I find a lot of what my family tells me about race and dating to be reprehensible, but if they were to say something like this about the race that we all are and that I'm semi-expected to marry within, it would be very different from when they stereotype other races.

How about "Don't ruin your future"? It doesn't matter what the cause is: "man", "good man", "purple man", "flesh-eating bacteria", etc.