I've had a heck of a time trying to come up with a name for our second daughter (due July 16). My first daughter also is an Addison (Addison Makayla Peters) and we call her Addy. I saw the post about Baby Hopes and the name Emerson really stuck out to me, except maybe spelling it Emersyn. So far, that's the closest we could come to agreeing on a name. The reason I like it so much is the nickname, Emmy. Our choices for a middle name are narrowed down to McKenna (after her grandfather, Ken) or Nicole (my middle name). Is Emersyn to matchy-match with Addison? I'm not sure if we're done with just 2, so if we had another baby I'm thinking that changing the ending to "yn" would open up more of the "n" ending names, IF our third is a girl. We're also leaning more towards Emersyn Nicole so that it's not too matchy and we would be stuck to come up with a "Mc" sounding name IF we had another girl. I'm open to other suggestions for names, specifically those that might get me to Emmy, because I think I've fallen in love with that! Other names we've considered are Riley (but no good NN), Sidney, Kinley, and Hayden.
Names to get the nickname Emmy:
I see what you mean about avoiding the problem of feeling obligated to continue the son/Mc name structure. Emerin might be the perfect name for that: very similar to Emerson, but without the -son ending---and it gives you the Emmy nickname you're looking for. You could spell it Emeryn if you preferred. Emeryn McKenna is a little heavy on repeating sounds (lots of E, M, and N), but not so much that it's out of the running, and Emeryn Nicole is nice too. Or perhaps Emerin McKenzie for more sound variety.