She self-identifies as a “broker.” The First Amendment does not provide freedom from consequences. If she doesn’t want to be treated as a broker, don’t call herself one.
The Supremes just ruled on ObamaCare that it doesn't matter what you call things. It can be a tax even if you say it's not a tax. I would assume that she is not legally a broker even though she calls herself a broker. If she's not taking a commission, she's merely using the word "broker" as a convenience for the customers so they will find her as person who can list their home as for sale.