I would recommend the opposite of the answer of Brian Krause unless you have explicitly been told in the past not to submit things. You aren't going behind her back, you are just being professional. It seems to me to be a mistake only to try to counter explicit instructions.
I'm assuming, of course, that the work is yours alone and that shared authorship is not an issue for this work. If it is not yours alone then you need permission from your collaborators to publish and they may have a right to shared authorship. In some fields almost all work is collaborative. In others it is almost all the work of a single person.
However, there are two other issues. One is the payment of conference fees and travel expenses. You can't really expect her to cover these unless she has approved of them in advance. The other is how to deal with the time you will spend away. If others depend on your presence, say in a lab, it could be disruptive.
I would suggest that you submit, but expect that you might not be able to actually attend. Sometimes that can be worked out with the conference committee and sometimes the author has to withdraw, which can be a bit embarrassing.
But it seems a mistake to me to make a decision based on what she might do. Just be prepared for what she does and to accept final decisions if necessary.