A C/S will not stop her haemorraging. It would actually most likely make the situation worse as you loose so much more blood from the surgery then a vaginal birth and then add a haemorrage on top of that. Some women that haemorrage every time after birth can be hard to stop this happening but you can lessen the degree if you act immediately after the birth. Like administering certain drugs to help like syntocinon or syntemetrin.

We also use different drugs like misoprostil which is very effective (its a tablet thats put inside the uterus) or a balloon cathetar which is also put inside the uterus and filled with approx 500mls of warm water. It puts a volume inside the uterus so it doesn't need to contract as strongly to stop the bleeding. Its is then removed the next day after the uterus has had a chance to contract well so once its removed the uterus will generally contract back down to the size it should be with minimal bleeding. If its has happened to your friend every birth its most likely caused by poor uterus tone due to poor contractions post birth ( from a tired uterus) not retained products or blood disorder (if it was this she probably would already known she had a clotting problem) so the balloon would be very effective in controlling the bleeding. Most birthing hospitals have them. But they do tend to use the Synto infusion before using a balloon cathetar or misoprostil.

Where she plans on birthing the staff should have everything prepared for a PPH going from her history. Hopefully she wont haemorrage at all but if she does they should have everything in place to keep it under control.