My daughter trapped her thumb I. A car door?

She now has a swollen thumb this happened two days ago and I really can't bear to look at it it turns my stomach! She's fine in her self and doesn't seem to have broken it as she can out pressure in it! But it has turned black and today she caught it near the cuticle and it started bleeding, it still looks really swollen ! The nail it stuck up more at the cuticle than at the end do I cover it to stop her knocking it or do I leave it?