Son: I don’t wanna be blamed for their mistakes.
Mom: But, sweetheart, the only person that anyone thought made a mistake today was you.
Son: I’m sorry.
Mom: It’s okay. I get it. I haven’t been the best example. But, you know what? Mommy’s got her hands on the wheel.
Question: May I know what the last sentence means here? Is “hands on the wheel” a real phrase that you use?
My guess is that means, that mommy has got the situation under her control. Or she has got her behaviour under her control to be a “better example” for her son. Metaphor of control. Implying the “steering” wheel of a vehicle.
To have your “hands on the wheel” is to be paying attention and to be taking control and care of a situation.
In the US, a number of years ago, there was a song that popularized this idiom called, “Jesus, take the wheel.” This phrase is a simple prayer-like request for divine intervention in a situation. This example phrase can be used both seriously and humorously.
The opposite idiom is “sleeping at the wheel” which means to dangerously not be paying attention or be in control.