Soft tissue damage usually hurts worse than an actual break. You might buy your friend a tube of arnica gel. Arniflora is one good brand and then there are a lot of others at your local health food store.Suggest to your friend that she keep the tube on hand and also some of the homeopathic remedy as well.
The father is being abusive and neglectful by not getting the child looked at and this worries me more than the actual injury. Your friend needs to talk some compassion into him, but if not successful, seek some counseling.
The injury might actually be a structural one that involves the head & neck. If so then the ankle will never feel "right" even when the pain goes. Your friend can call the web site www.pettibonsystem.com
and get the "800" phone number to find a practicioner in her area.
I learned this the hard way with my own son-not by neglect but ignorance. With the proper treatment and getting the head aligned on the spine correctly the injury will heal.