Install a trigger for Ashley to fall in trance

You: "That's right, Ashley. Just listen and obey my voice."

Ashley: "Listen and obey ... to your voice."

You are fascinated at the mindless state your stepdaughter is in. You know this trance is very short and you're not even sure what to say. Then you have an idea to solve this problem.

You: "Ashley, you are now in a deep hypnotic trance."

Ashley: "Deep... hypnotic... trance..."

You: "Whenever I snap my finger and say your name you will fall back into this hypnotic state. You will be just as mindless and obedient as you are now. Completely entranced. Completely receptive."

Ashley: "...Completely entranced... completely receptive..."

You: "That's right. Anytime I snap my finger and say your name you will fall into a deep trance and you will accept everything I say."

Ashley: "Accept... everything..."

You: "Anything I say to you while you are in trance is true. I can completely change how you think and how you feel. I have complete control over your mind while you are in trance."

Ashley: "Complete control... over my mind..."

You: "Yes Ashley. Whenever I put you in trance you can do nothing but listen and obey my voice. You'll be in this state until I tell you to wake up. Do you understand?"

Ashley: "Yes... I understand..."

You: "What happens when I snap my finger and say your name?"

Ashley: "I will fall deep into trance... I will be in... hypnotic state... just like this... Completely receptive... Only listen and obey... You have.. complete control... open and receptive... until you tell me... to wake up..."

You: "Very good Ashley. Now..."

[BEEP] [BEEP] [BEEP] [BEEP]

You: "...It's time to wake up I guess."

You press the button on your watch and wait a few seconds. Ashley's eyes refocus on you.

Ashley (annoyed): "What?!"

You: "Can we please talk like grown-ups for once?"

Ashley: "There's nothing I want to talk about with you, so please just let me eat in peace."

Ashley focuses her attention on her breakfast again and continues eating.

You: "Come on, Ashley..."

She ignores you and pulls out her phone.

You (snap finger): "Ashley!"

Ashley doesn't react. You wait a few seconds. Neither the fingers on her phone nor the hand holding a spoonful of cereal is moving. Her eyes stare at her phone. But they are unfocused and empty. Looks like this works.

You: "Ashley, look at me."

Ashley looks straight at you, and for a second you think she is gonna shout, but nothing. Her eyes are not exactly as dull as in the serum-induced trance, but she is clearly out of it.

You: "Describe your current state, Ashley."

Ashley: "I am in a deep hypnotic trance. I am completely mindless and obedient. Completely mesmerized. Completely receptive. I will accept everything you say. Anything you say to me is true. You can completely change how I think and how I feel. You have complete control over my brain. I can do nothing but listen and obey your voice until you tell me to wake up."

Her monologue is fast and sounds almost mechanical. Her manners are different from the state of trance she was in just before, but it seems to work nonetheless.

Now you just need to come up with something...