What do you mean when you say you've "already warmed her up"?
If she is already aroused, of course she's going to be more sensitive.
In my experience, while many women enjoy cunniligus......after a while, they become so sensitive than if you to continue for too long (this varies from woman to woman)...., that, for some, it actually starts to become unpleasant.
Let her guide you to what rings her bell and what doesn't......