Milking goats need the high protein in alfalfa. When mine are dried off they get grass hay. Wethers shouldn't get grain or alfalfa because they don't need the high protein as it will cause urinary calculi. But, if you can find a good dairy ration for goats (16% or higher) or maybe buy a 4-way feed (it is cheaper than dairy goat ration) and add sunflower seeds in the shell (helps with fat%), beet pulp and the calf manna on it as a top dressing. I put a handful of each on their feed. I feed about three cups of grain at each milking and they get about 1/2 flake of alfalfa in the morning and at night each. I bet once you start her on some alfalfa (introduce it slowly as well), she will pick up her milk production.
I would give her maybe 1/4 of a flake to start with and work up, the same for anything you add to her feed. Go a bit slowly, you don't want to upset her digestive system and end up dealing with diarrhea.
As far as a wormer goes - we live in a very dry area and worms generally aren't a problem. I seldom worm my goats - but, I have used an herbal wormer that Hoegger's Goat Supply sells. I like it because there is no milk withdrawal time. Some of those horse wormers have a two week withdrawal time. The herbal wormer is a powder you sprinkle on their feed. It is made of wormwood and they seem to like it. Most people worm after their does kid. If you are in a wet, humid area, you may need to rotate your wormer medicine if you plan on sticking with the horse-type wormer, because they get resistant to the same wormer after awhile. But, I have always had good luck with the herbal. Hoegger's is online - just google them to see what they have.
Bonnie