My mom always calls me
Emily (my sister's name), and
Aileen and
Emily aren't very similar.
Keely and
Kelly would just be... ridiculous. One has a long E sound, the other a short E sound. That's the only difference. Twins are two completely different people. Why try to give them nearly identical names?
I'm also not crazy about
Kelly Catherine. The alliteration is just too much. My first thought was
Kelly Cecilia. What do you think of it? I'm personally not wild about
Cecilia, but I think the combo is quite nice. Plus, it still begins with a C, just a soft C rather than a hard C.
I also agree that
Eric Patrick and
Sean Nicolaus are excellent combos. Try to stick with similarly classic names for your daughters. That way they'll go well together without being matchy. Good luck and congratulations!