OP - MB here. I would find a new nanny. or nanny share. Kids are adaptable. More so than you think. I've already gone from nanny share for a year, to a daycare for a year and now a new preschool. I'm not proud of all the change in DD's life but she's remarkably well-adjusted, loving and seems okay. I think that as long as there is some consistency in DD's life (in this case, me and her dad make a point to spend a lot of time with her outside of care situations), they will be fine.

Doesn't speak English well and doesn't drive? You're overpaying big time and she isn't professional given the way she handled it. I no finding a new nanny is a pain but for your children's sake I'd do it.

+100 I'll also add that she has gotten to the point where she thinks she can manipulate you and give you ultimatums. This will not be the last time she pulls this if you reward her with success.