Supplying zero info as to why your friend needs more blood, makes your question a huge question.....if you want to learn, naturally that is going to be too late for your friend and no doubt if they believe in their doctor, they have already had some blood....

So ideally your friend needs to learn, but until then, it may be up to you, so I suggest you learn all about orange juice fasting and about herbs known to help build stronger blood, but with out knowing anything about your friend.....there are hundreds of reasons in her case she may be dying.