twin names

I think Naomi and Nadine go better together.

I don't find either Margo or Neeltje very nice. But Margo is better.

100% sure, Margo! I think it's a really beautiful name. Timeless, classy, sweet and tough at the same time. And it can be pronounced across different language borders, which is a plus in these times! I personally prefer the spelling 'Margot' because that's the classic spelling, but Margo is also sweet and nice.
Neeltje, honestly, I don't find it great at all. I think it's a name that wouldn't suit every appearance and personality. It feels more like a pet name than a real name to me. Nell, I do like very much! Nele and Nelly, for example, I think could work too.
By the way, I also think Naomi is super! Again, so sweet, girly, not too special but still with a special sound. Great choice!
So I vote wholeheartedly for Naomi and Margo! It's also nice that the a and o appear in both names and that both names start with a nasal sound (n and m). While the names are very different and you don't get a quack quack quack effect. Super!

Naomi and Neeltje! Really beautiful! Same letter but completely different names. Nice for twins! I don't really like Margo. I find it old-fashioned and I never know where the stress falls. I can imagine people think Neeltje is an old name too, but I know a very sweet Neeltje who's 2! I think it's a strong and lovely name that fits well with Naomi!

I think Naomi is really beautiful, but Neeltje and Margo both feel too solid. Sorry!
Naomi is cheerful, lively, and melodic all at once, and with the other names I picture sturdy women.
I see that Nele is suggested. I find that much more lively (but it doesn't quite match up to Naomi).