um.. refeeding is very dangerous, and should not be done. here is a link to information about it.....Refeeding Syndrome | Nutrition411

if she is in this phase of recovery she should be in a hospital setting where they can have her eating based on what her body requirements are.

another thing to consider... some people who get like this their parents have been court appointed for making mental and physical health decisions. if this is the case then you may actually be committing a crime (kidnapping and others) if her parents have no idea where she is, what treatment she is receiving and such things that the courts may have designated as the parents choices not the 21 year old. (not always but most times theres a reason why a 21 year old still lives with their parents and their parents are over seeing that persons health issues.)

I know you are just trying to help this person which shows you are a very kind and caring person but with out all the information and the medical\psychological qualifications needed you could accidentally be doing more harm.

my suggestion is not to lie to her parents. ohio does have adult protective services that can do an investigation to whether the situation is a dangerous one and they can get her into special services that can help her. contact your social services adult protective services department.

bottom line is if you are not her treatment providers and not her guardian you could actually end up doing more harm than good for her by attempting to re feed her, not to mention if something happens you could be held responsible through the justice system.