Her physician needs to contact a doctor in the city where she is going and send them her latest medical information. She should also travel with a copy of her records. I can't tell you the cost, but I know that where I live, if you know someone who needs blood you can make a donation to the blood bank and dedicate it to the person that needs it. It doesn't have to be the same type. They take your donation and give the correct type to the person needing it. Then there is no charge for the blood, but of course there will be expenses for the transfusion So, if that is the way that it works where she is going then, yes, your wife can make the donation if she meets all the health qualifiers.