IJM,
a sponsor has one task: to be a guide through the step-stuff. to do that in an honest way.
being available, also.
but the point of doing the step-stuff is to "grow" your relationship with a power greater than yourself, however you define that.
sponsorship is not about being friends and going to dinner with a bunch of others. that might feel nice but isn't sponsorship.
maybe get hold of the AA pamphlet on sponsorship and read up on it?
as you can see, instead of getting focused again on "the work", you're now wrapped up in feelings about how you're being treated, if you're friends still, if dinner invitations will be extended...."feel good" stuff that is interfering with what sponsorship needs to concentrate on.
possibly she's realized that she was involved with you on an unhelpful level. trust between you is important, but ultimately the sponsor's job is to help you develop trust in a power greater than yourself.