Horses have completely different insulation systems than people and I don't think relating the two is completely accurate.
OP, I'd work on getting her up at least 50lbs, she does look like she has lost quite a bit of top line from the previous photos. Just get a feed schedule on lock with your BO, if you're worried about being kicked out read over your contract and see what is allowed/ not, but I would hope for you to be able to communicate with BO about such things without a big deal.
We are not human beings having a spiritual experience. We are spiritual beings having a human experience. -Pierre Teilhard de Chardin