Is it just a prestige thing you're after? So you too can say "Yes I study with Professor .... instead of just Mrs..."
Just food for thought.
I had a student who WAS studying with a professor of music at our local university, and she changed to come to little ole me - with just a humle arts and teaching degree. That student now teaches as well.
Only when things start going wrong, or 'standing still' would you need to think about going elsewhere, and then you would want to make sure the person you go to is actually going to be of greater benefit to you.
I'd also recommend including your current teacher in the search. Don't go behind her back (that is, if you ever do decide it's time to go somewhere else), but ask her for advice. She's seemed to have your best interests at heart for all these years. She may even have contacts you don't know about.
But like others have already posted, if it aint broke, don't fix it!