Police say Margaret Dougherty, 41, ran the brothel out of her home on Ardmore Avenue in Upper Darby.
However, it was only open during the day while her son was in school.
The other woman arrested, Amy Prudish, 38, of Riegelsville, is alleged to be one of the prostitutes.
Upper Darby Police Superintendent Michael Chitwood says his department was tipped off by concerned neighbors and an ad for "massages by beautiful women."
Police say an undercover officer went to the house was greeted by Prudish, who offered to perform sex acts for a tip.
The officer refused but came back the next day, where he claimed Prudish agreed to accept $200 for sex.
That's when police moved in and arrested the women.
Officers say they also found log books filled with names, dates and phone numbers. Guns, a computer and cell phones were also seized.
Chitwood said Prudish, a single mom of two, had built up fairly large clientele base since the operation started about a year ago.
"She would only come down if there were at least four clients available for that particular day, and they would run the operation from 11:00 a.m. until 4:00 p.m.," Chitwood said.
He also added that this investigation is not over yet.
"We believe there were several other women involved," Chitwood said. "Right now we've closed them down for good, hopefully."