I don't think you have anything to worry about. I sometimes submitted abstracts then informed people afterwards. You don't even have to tell anyone. As AnnieG says, you will name yourself as the corresponding author. Even if there are other authors in your submission, responses will be sent only to you.
It's a shame your supervisor has outdated views. While she may have reservations about PhD students presenting, she should realise there are other things you can benefit from, such as learning how to put a conference abstract together and about the submission process.
Does she have similar views about PhD students getting published?