Thanks. This is my first time on any forum so I hope I'm doing things right here. I wouldn't be so worried if it was in the spring or even summer, but I know winter kills...
A little friendly advice:
Even if the forum is pretty much required to be a friendly place, which means that many knowledgeable people will keep their jaws wired shut...
There will be a few people who will flat out tell you when you're doing something wrong, and question. The gravity of the situation will alter how blunt they are.
Which is to say, your situation is a bit out there.
Your mare was bred? Unplanned? Why didn't you get the vet out to give her a lute shot to prevent the pregnancy?
Yeah, the other horse is worth money, great, but not if she's sick or dead...and if finances were so tight after the injury, why not sell or rehome her?
Just some things to think about. I'm sure other people have other insight. Just as I'm sure there is some "good reason" you didn't do these things.