There is really no way to answer your questions without more information. You have a huge potential mess on your hands, because this was apparently never properly taken care of. The title of the house would appear to be in your grandmother's name. That means that an estate would need to be opened for your grandmother and a personal representative appointed by the court. If your grandmother had a Will, then the property would pass according to the terms of the Will. That might mean that your mother was the sole beneficiary, or it might mean that ALL of the grandchildren are now entitled to a share. There could potentially be the need for separate probate estates for each of the deceased children. Whether or not your mother has an offset for the expenses that were paid is open for argument. The counter-argument is that she *should* have been paying rent. This is a mess. You may have tax issues, you may have insurance issues. For example, since the house is apparently owned by your grandmother, it may not be insurable, unless an estate is opened. That does not mean that you do not HAVE insurance. But if there is ever a claim, and the insurance company has not been notified of the situation, it may refuse to provide coverage. So you may have been paying for insurance coverage for 25 years, that was not there.
Answered on Jan 07th, 2013 at 11:34 AM