For much of Resident Evil 4, Ashley will be by Leon's side - his job is to protect her, after all. However, being a university student, Ashley is not trained in combat and is useless in battle. Therefore, she must be called to "wait here" while Leon advances, or "hide" in nearby crates until Leon whistles to signal the all-clear. If Ashley is grabbed by a Ganado, he will take her to the nearest door. If she is taken out of the area, you will lose the game. You must, therefore, take priority in killing the Ganados near Ashley. Should she be captured, shoot the Ganados in the legs - you cannot risk hitting Ashley, as any hits from gunfire or knife-slashes will lead to an instant death and game over.
Ashley will not jump down ladders, the player must stand by the her and use the "CATCH" command prompt to catch her. When away from Leon and in danger, Ashley will scream "Leon, help!!" to signal the player.
In some point of gameplay, Leon have to let Ashley operate cranks in higher place where Leon cannot reach (in the castle). In some instance, Leon can have a choice to operate the cranks and switch himself or ask Ashley to do it (like the wreckling ball).
While wearing her Special 2 costume (the suit of armor), Ashley is unable to be killed and can not be damaged at all. When enemies attempt to kidnap her, they will fall over due to the weight of the armor. Also, when Leon catches her using the "Catch" command prompt, he show sign of back pain. When aiming in her direction as Leon, instead of ducking Ashley's visor will lower. Ashley not ducking means she can potentially block the player's shots, and block arrows aimed at Leon.
For most of Chapter 3-4, Ashley will be controlled instead of Leon. The amount of health she has is based on how much and how far it has been extended by giving her Yellow Herbs while playing as Leon. Her inventory screen will use the default size which starts out empty. Ashley does not have a knife to use and during her gameplay segment, there will be no weapons to equip and use either.
The player can find ammo and health items and be given the chance to place them into Leon's inventory once reunited with him. Pesetas and treasure items obtained will be automatically transferred.
While in the Study, the player will encounter two cultists. Unlike the rest of the game where these enemies try to carry Ashley away, they instead will attack by using the strangle move. While here, the player can only defend themselves by throwing the lanterns in the room using the command prompt. The lanterns respawn by moving to the next room and then going back in. In the GameCube versions, Ashley can suplex cultists if the player hits them when opening a door. This was removed in all later versions.
Getting killed by the cultists will show them carrying Ashley her on their shoulder and leaving during the "game over" screen. The Armaduras leave her on the ground.