I'm very honest! And a BIG Congrats if you're expecting!
Nash is cool, kinda sounds country. Ah, don't go with something too off-the-wall (i.e. Ganon) since he'll have to continuously spell it out for people and repeat it over and over. People will hear Cannon.
My philosophy on names is I like unique but not too odd, and I like names that are easy to say and spell for the child's sake. What is the pronounciation of Evalett? Is it a silent "t" at the end, as in Ee-va-lay or..... is it Ev-ah-LET. I just don't get it..never heard of it so am confused by it. She'd be explaining that her whole life.
What about Gage for a boy? My friend named her son that and it sounds so cool. Or I like Gavin. And I guess Grier is the best girl name and I think (going on your style) Evelyn is OK (more easy to say and spell, and you can shorten it to Evie, since you like Evalett.)
OOHH...don't like Gretchen!!! (Gretchen Retchin...sounds like an old, crabby lady who hates kids on her front lawn.)
GL in being pg and have fun deciding!