Loosen the screw on the broken lock frame on the mobile home window. It will be located either on the side of the lock facing away from the window or the side of the lock perpendicular to the window.
Adjust the lock frame on the aluminum window. If it’s the type of lock that you slide up to unlock and down to lock, readjust it over the slots in the frame of the window. The lock frame should cover all of the slots. Loosen the screw to widen the lock's mouth and slide it over the slots on the window frame.
If the lock is the type that slides open and closed with a latch, adjust the frame so the latch can catch on the hook inside of it. Move the latch back and forth until it catches the hook to adjust it.
Tighten the screw on the lock frame once it’s repaired.