Cowan was one of three unanimous selections to the team.
The 7-foot-2 freshman committed to the Terps in May.
The Terps will return all five of their starters from a season ago and welcome the No. 3-ranked recruiting class in the country.
The Terps will play home-and-home series against Iowa, Ohio State, Illinois, Indiana, Northwestern, Rutgers and Michigan State.
Cowan led the Terps with 15.6 points per game last year.
Coach Mark Turgeon secured his fourth recruit of his 2019 recruiting class.
She averaged 1.5 points and 8.9 minutes per game during her three years with the Terps.
Ramsey appeared in five games in his freshman year.
The Terps' top-two scorers plan to hire agents but can still return.