I'm really glad to hear that you went to your doctor - it is a tough thing to do, but it is important to your health and the health of your family/relationships - you should be proud of yourself. It sounds like she's really on the ball and that 'inventory' seems like a great idea to help with objectivity.
I'm a complete lightweight when it comes to medication and can't tolerate very high doses. I have Bipolar and most people with BP average 3-4 meds while 2 was my max. I can't speak from direct experience with Wellbutrin and Prozac, but I can in regards to using more than one med (Effexor and Depakote). If you have concerns talk with your pharmacist - its their job to help you find answers. In my case, taking two medications simultaneously allowed me to take less overall. I know that it sounds bizarre, but my doctor explained that some medications basically piggy-back on one another making each other's effects more pronounced without an increase in dosage. I think that the attempt is to try to accentuate the positive effects of each med without increasing doses which would usually increase any side effects. Since the wellbutrin worked for a while, your doctor might be trying the prozac to see if it will boost the effect rather than going through the challenge of a whole different med.
Hopefully someone with more specific experience can reply and let you know how it worked for them. Take care of yourself and good luck with the new options,