Your "friend" needs an attorney, because only her brother may claim she is a "licensee" instead of a co-owner of the property.
In a licensee holdover the petitioner is not required to prove a landlord relation with the respondent: A claim that the person entered into possession without a lease agreement - in other words, became an occupant by reason of permission given by a person who had a right to possession - allows a new person claiming a greater right to possession to terminate the "license" and demand the occupant vacate the premises. Based on your statement about your friend's possession, she had as much an interest in the possession as her brother and cannot be a licensee.
In order for the brother to prove a greater interest in the ownership of the property than your friend the brother had to succeed their mother as the lawful owner of the property. If he has a deed he is the owner. Based upon your information the mother did not intend one of her children to have a superior right than the other in the house.
Exploring how the brother acquired his deed is important to defending your friend's right to continue to live in the house.
Winning her case in the AVVO forum is not the same as meeting an attorney for a face to face review of all the salient facts, that an attorney may discern. Hiring an attorney to defend her right to possession against her brother's claim is essential.
The answer provided to you is in the nature of general information. The general proposition being that you should try to avoid a bad outcome if you can.
Your friend needs to have a lawyer evaluate the brothers claim to be in exclusive title to the property. If the mother died without a will and there are only two surviving children your friend may be co-owner with a right to bring a partition action. and certainly has a defense to a licensee holdover proceeding.