Preheat oven to 375 degrees. Unroll pie crust into a 9-in. pie plate; flute edge. Bake for about 15 minutes or until golden brown. Set aside.
In a large bowl, combine peaches, strawberries and lemon juice. In a small bowl, mix sugar and cornstarch. Add mixture to fruit and toss gently to coat. Spoon into crust. In a bowl, mix flour and brown sugar; cut in butter until crumbly using a fork or your hands. Sprinkle over filling.
Bake on a lower oven rack until topping is golden brown and filling is bubbly, about 50 minutes. (If edges get too browned, cover with foil.) Serve with vanilla ice cream.