Under the given set of circumstances, you would definitely need an attorney. Your daughter is an adult now and you'll need a new report, a doctor's report, which states she is unable to handle her personal and/or financial affairs. Financial affairs come into play if indeed your daughter receives any sort of state assistance because by such, she has an "estate" which needs managing. Guardianships are not only granted for folks that are mentally & developmentally disabled, but also for those who because of some behavior (i.e., alcohol, drugs, gambling) are rendered unable to properly manage their own affairs. Your daughter, being 25 will have some say in who is appointed as her guardian and if this older woman is as cunning as she sound, she may influence whom your daughter selects or at least indicate your daughter should vehemently oppose any sort of guardianship if she legally can. Unfortunately, guardianship isn't something you can take your daughter by surprise with. She has to be given notice. I strongly suggest you consult an attorney. It sounds as though you really love your daughter and that you are living the nightmare of many a parent. Fight for her smartly by investing money in a good attorney or beg one to do the guardianship for you pro bono. Best wishes to you and please and know that you will not always be sen as the enemy by your daughter.