I pretty much second what has already been said.
My other thought (on the alfalfa front) is to just get a single bale and try maybe adding a 5 pounds to her ration per day.
At least with my Lacey girl, she starts dropping weight like no one's business in the winter without her alfalfa. I had been trying, this winter, to cut out the alfalfa just because it's not recommended for her given her propensity towards obesity etc BUT I'm going to have to "give in" this next week. She's been eating 30lbs of grass hay a night, grazing during the day in her pasture that actually HAS grass, and getting 2lbs of alfalfa pellets/day, as well as being blanketed 24/7, but she's already ribby (as in, you can see rib pretty easily when she doesn't have a blanket on) after just a few weeks of 40*F weather+rain.
In the past, I've found that even just a single flake of alfalfa/day (about 5lbs off a 120lb bale) is enough to keep the weight on her. That ends up working out so I only need to buy alfalfa every couple of weeks (I only have room to store about 6 bales so I generally buy hay on a weekly/bi-weekly basis). At $15/bale doing it that was is significantly cheaper than alfalfa pellets (40#bag for $12). Just a thought.
Feeding alfalfa is really where I slash my feed costs. If I tried to feed A pellets and grass hay (as I'm finding out right now) things are SO much more expensive and the weight just does not stay on. For example, I'm currently spending about $25/week on hay+pellets alone which is ridiculous. For the last two winters, feeding alfalfa, I've been able to spend only about $12/week (since grass hay is $5/60# bale and she maybe eats 15#s of it per day when she has alfalfa).
On the front of supplements, I'm currently feeding Lacey Nature's Essential's 12:12 (I don't feed it free choice, I add 2oz to her feed/day) and 1oz of Red Cell to get her "everything". With alfalfa+all that, it evens out for me. The NE comes up as "not recommended" for a laminitis-prone horse, I think, BUT that's due to how FeedXL doesn't have "all" the info on it. It's literally just minerals, no sugars etc. :)
Fabio - 13 year old Arabian/Lipizzaner gelding
Hazel - 14 year old Angora goat
Atticus - 4 year old LaMancha/Alpine cross goat
Rest peacefully, Lacey.