I have a Luna. I think it would be a bit odd for her to have a sister called Kelly. Of course it doesn't matter, just so different.
For example, twins called Frank and Robyn just sound like they go together to me, neither bame seems out-of-place. But receiving an invitation to "Frank and Diamond's"?.
Idk. It's jarring to me.
Not to say it's wrong but it bugs me. Likewise, matching middle names to first names. So I always loved Alice Josephine & Violet Ramona as a teen (not so much now), but I wasn't as keen in Alice Ramona and Violet Josephine. Reason? The colours I associate with the names don't march as well that way. Alice and Josephine are both pastel colours to me, whereas Violet is violet and Ramona makes me think of brown and dark green (hence why Violet Ramona works in my head because they are jewel like colours and also the flower in the earth image).
I don't associate all names with colours, some are associations of mood or time-period. Maude to me is a very sad name, a bleak name, and makes me think of the 19th century.
Sonny, on the other hand, is a bright name, a happy name, it's yellow (sun) and makes me think of the late 20th century. Maude and Sonny would clash.
Probably won't bother the kids but it really irritates me.