I started competing through the pro/am side. While I learned much from my instructor, I found it frustrating to not be able to practice the way I wanted and that there was limited competition for pro/am men due to the countless age/level categories. After my first competiton, I decided that I wouldn't compete again as pro/am. When the opportunity for an amateur partner presented itself, I took up the offer.
If you are interested in competing, switch to the amateur partnership. If you want to maintain some continuity in your training you could use your pro/am instructor as a coach. If you want you can always compete in both amateur and pro/am partnerships.
I wouldn't worry about how your instructor feels about you dancing with an amateur. This is a business relationship. If she gets mad at you or tries to play on your emotions, she obviously does not have your interests in mind. If this is the case, you should find a new instructor who doesn't play silly games with you (whether you dance pro/am or not).
Blair