The Nittany Lions couldn't muster much offense in a sweep by Lewis.
Dylan Lugris delivered the game-winning goal in round four of the shootout over the No. 1 team in the nation.
Walfe, who has four years of eligibility remaining, transferred from Michigan.
Captain Tessa Janecke tied the all-time points leader with an assist to Abby Stonehouse.
The junior announced on Saturday he would return for his senior year.
No, Drew Allar's interception wasn't the only reason behind Penn State's elimination from the College Football Playoff.