To the left of the vulva where her tail is covering part, it shows swelling. I could use a cool towel if the water lines are fozen. The pinkish part also looks kicked , I would put triple antibiotic, on my Mare that got kicked (mare fight)
I put the biozide ointment on it.Not a lot,but enough to keep it from getting irritated from Urine or feces. The lumpy portion at the top, It may be from having caslicks done since she was a broodmare.
Somone had posted that the blood was from being in heat.. No, it will be a whitish discharge Not blood. Her Uterine is way up there, so I doubt if her uteris is damaged. I would not use ice. Cool water, you can use a wet towel then pat her dry and put the antibiotic ointment on her.