My DS had a sensitive gag reflex, too, and it took us until he was closer to 11mo to even get to stage 3 textures. I don't think teeth make that much of a difference one way or another (DS had all but his molars in by the time he was 1yo).
Personally, I did a couple of things...well really 3:
1) I stopped trying to worry so much. As long as you're conscious of where she needs to be heading, you're doing great!
2) I focused on one meal a day to introduce the finger foods/thicker textures (also helped with #1). That eventually spread out to all meals once he got the hang of things.
3) I gradually increased the texture/thickness of his food. For example, those stage 3 jars with the chunks of stuff...I started off mashing up the chunks. Once he could handle that, I mashed them less and less and less until he was able to eat those.
HTH a bit! There a lots of moms here who have wonderful tips and suggestions; I'm sure they'll chime in, too.
