R.S.
Hi there,
My son went through a similar phase about this time. He on the other hand would wake up screaming and it would last for hours until we learned how to calm him. His pediatrician told us that this was about the time children begin having nightmares so that could be causing it. And also when they begin to start having some separation anxiety from mommy and/or daddy. He said it is very common for children of this age to have a major change in their sleep patterns. Of course as you mentioned and the others as well she could be teething too! It's a difficult time for parents during the early years because our little ones can't verbally tell us what's troubling them! Hopefully it won't last long!
Good luck!