I was always barely keeping up when pumping. The herbs and stuff didn't work so well for me. You're probably already drinking an extra lot of liquids, that's important. Maybe in the morning you could pump before breastfeeding, then her work will get the most out of the breast, get rich hindmilk and work on increasing supply. Your supply is highest in the early morning, and lowest between 6 pm and midnight. I don't know if it's worth playing with the same pumping before feeding in the evening, because your body just might not be able to meet the demand at that time no matter what. Sounds like you're pumping a little extra on the days off? I would try the same thing, pump before feeding. Your milk also has the highest fat content in the morning, which is good for nutrition and keeping her full.
Kellymom.org (or .com, can't remember) has some good tips. Good for you for working so hard to keep breastmilk going for your baby. I hated pumping, myself. It also helped me get more milk pumping when I did a meditation practice while pumping. I didn't have the best pumping environmnent.
Asians believe that leafy green vegetables boost milk supply, so you might try to increase your spinach intake. I found that when I chop spinach, chard, or kale in the food processer, then do a light grill in a cast iron pan with some olive oil and water, I can eat a lot more of it. I also found broccoli rabe at whole foods, which is leafy broccoli and has great nutrient content. I eat them with eggs in the morning, fish or tofu for lunch or dinner. It seemed like a lot of work at first, but now it's easy. I also found out that when you eat tofu and seaweed together, you get the most out of each of them. Sometimes I mix those into my eggs. Oh, I also starting using coconut milk in things while I was nursing, that has good fats for milk supply, and for the baby. There are lots of ways to use it, I put it in the rice cooker instead of water, I poached fish in it, added it to sautes, stir frys, and scrambled eggs. Dietarily, I've heard that it's most important to have a high protein breakfast, so you might want to have some oatmeal in the evening instead, which is also supposed to help milk supply. I know it's hard to imagine re-habbing the diet when you've got other things draining your brain, but I found that I could do it by just keeping it simple: protein, little bit of rice, lots of veggies, not doing anything fancy, just saute with olive oil, and add ricotta cheese or balsamic vinegar.
best wishes.