Help my mother keep her home

Hello my name is Nathanael and I am trying to help my mother save her home. She has been taking care of this home on her own with my two autistic, younger siblings. My father left over 13 years ago and just passed away this week. We have just found out that he (my father) has tried to split the property and sign over his half to the girl he was living with, even though he has not spent a single dime since he left in paying child support or anything for the property. Though this has caused extensive financial and emotional termoil to my mother, this is the only home my siblings have known, and to lose it would be beyond devastating. Please help them keep it by any donation you can make. Thank you.