dean | Points

film has 3 characters , 2 men 1 woman , they end up in an asylum i think but escape , they walk along a high wall , woman with a black umbrella, a dog walks below, they come across a school, children...

Maybe "Silent Running" (1972)? https://en.wikipedia.org/wiki/Silent_Running If this is the movie you are looking for, then please select my answer as Best Answer by clciking on the "Select" button.