It sounds like you really love these rings. Why not get yourself one as a treat? My parents bought me a diamond ring when I was sixteen (a tiny stone, pretty setting, but not my style). I hated it and never wore it because it looked like a tiny engagement ring and it only fit that finger and it wasn't my style.
So, your DD may not want one, or she may want one but not the one you want.
Since you are really into them right now, I'd say buy it and wear it for yourself as a post-baby-childraising present!