Sponsorship is a two way relationship. If your schedules are not working together, you should talk about it. If you cant work anything out between you two, you may want to find another sponsor. Not always an easy thing to do, but you want a sponsor who is available to work with you. If she gets offended by that it means her ego is wrapped up in sponsoring and that is probably not a good thing. But someone with quality sobriety will understand you wanting another sponsor.
Best wishes.