Pretty sure this is wrong. Shouldn't it be, "te olette kaunis pari"?
No, that means "you (plural) are a lovely couple". And one thing that this course seems to consistently get wrong is translating "lovely" as "kaunis" even though "ihana" is much more apt, at least in this context.
I believe Kaunis can mean pretty, beautiful, and lovely. We often say in US they make a pretty couple so I think this should be accepted.