Dear Dee,
Welcome to the LBD forums, First off I would like to offer that you go to the Lewy Body Dementia Association website
http://www.lewybodydementia.org/, When you get there look to the left and look through the many things they have and it will answer your questions about your "Mom" being agitated, she is NOT in control of any of her actions and I would think that legally the daughter has no right to do what she has done, your Dad does have legal rights being married to her and I think they have been over looked here with Helen's daughter.
You having no idea what meds she is on, this also can be a factor as I am sure you have read many are so bad for LBD.
Is agitation a major factor ? Yes my Husband was a calm gentle man most of his life and when he became ill it was like he was a different person, Good Luck!