The first thing that came to my head when I started reading this was oestrus, but that kind of bleeding in female animals is really only mild.
How much blood is there? Are you able to handle her and look to see where it is coming from? I'd explain how to look better to find out where but I guess that might be a bit too much to talk about on this forum? Ha I don't know...
Is she showing any signs of pain or discomfort?
Of course I would suggest taking her to the vet, but you've already said you can't. Is there any way you can take her and pay by installments?