As both a nursing mother and a peer counselor with Nursing Mothers Counsel, I can say that it's very normal for one breast to produce more than the other, especially when nursing and pumping. With my 3yo son, it was the left. Now with my 7wk old daughter, it's the right.
I have a few questions before I address your desire to increase your supply. How often are you pumping, and how many times in a 24-hour period are you breastfeeding? Are you double pumping? What kind of pump are you using? And how many total ounces are you able to pump each time you pump? Also, how long do you have before you return to work? The answers to these questions will affect what I suggest because you may not need to increase at all.
As far as one breast producing more than the other, if you're concerned about it, start her on the side with the lesser supply. Also make sure you switch breasts with each feed. ie: If you start with the right breast at one feed, be sure to start wtih the left at the next. If she feeds on both sides at one feeding, you can start with the same breast at each feed unless you feel that she didn't feed well on one side. Then, you can start with that side at the next feed. Within 3-4 days, it should even out.
I'd love to help you through this, so please feel free to email me at ____@____.com can also check out the Nursing Mothers Counsel website at http://www.nursingmothers.org. We are a non-profit organization of peer counselors who provide FREE one-on-one education & support for breastfeeding mothers at all stages :)