Sorry to hear about yr foal, awesome of you to offer yr mare.
I've been both sides, quite a few years back my A grade horse had a dummy foal, which died, she then raised a Sir Tristram colt, had a mare have a huge Tights colt, she haemorraged and we had to take foal off her, we put her down after 10 days, and my last breeding exercise, mare died within minutes of foaling, never saw her foal, got a fantastic mum for her, she saw foal and just had to have her.
Lifesaver for orphan foal owner if mare becomes available, I had a year old son when my mare died, getting up every hour and a half to feed foal, was very exhausting.