Do you have out free-choice minerals, also? If not, I would strongly suggest the goat minerals along with increasing her grain and adding alfalfa to her diet.
The alfalfa makes a HUGE difference in our girls' production.
Regardless of production, I would also highly recommend running a fecal. We worm all of our does the day after they kid to combat periparturient rise, so even if your herbal wormer has been doing the trick so far it may not be enough to handle the parasite bloom post kidding. Or, maybe it's fine. But it would be a good time to evaluate efficacy.