I love Jessie. I don't think I would go with Jessie Mae as it sounds very like Jessie J.
Reba is pretty. I haven't heard it before.
Like previous suggestions of Savannah and Dakota. I knew an extended family once who had these two names for cousins and also 2 other girl cousins called Atlanta and Sydney.
I also read a book with a character called Alaska which I like. And another one with a Tallahassee but I think that's probably a bit much!
Some of these might not meet your huband's 'no unisex names' requirement but I think of them all as feminine and quite American sounding:
Avery, Aubrey, Amberley, Addison, Alison, Angel, Asha, Brynn, Dana, Dina, Everley, Ember, Fallon, Giana, Gina, Harley, Halle, Harmony, Harper, Indianna, Joelle, Janie, Jennifer, Kendall, Leonie, Leona, Marley, Marnie, Mimi, Misty, Melinda, Nora, Nova, Piper, Quinn, Remy, Romy, Reeva, Roxanne, Rosina, Rowena, Stella, Saffron, Sorrel, Sadie, Skylar, Star, Tiana, Tallulah, Vivi, Veda