There is also the option of simply informing her that acting up in the manner she has done is not acceptable and that if it continues she will find no response whatsoever until she decides to behave. IE no punishments, and especially no funnishments etc etc.
She is an adult and can choose to behave can she not?
Basically what I am saying is: Attention seeking behaviors such as these are nothing new to the D/s dynamic.
A wise domme once told me that "topping from the bottom" is basically a bull shite excuse used by dominants who are not as dominant as they think they are. But one must also keep in mind it takes to at least two to tango in a D/s relationship. In other words it can't be a one sided exchange of power or intellect. She must choose too submit as much as you choose to dominate.
In your particular situation she isn't helping anything by being a brat or testing limits when amongst the uninitiated (such as your children etc).
If I did the same to my owner I would most certainly regret it later (we live in a household where I am my mother;'s home care provider and play time is hence restricted yet I am under his discipline 24/7...even if discipline isn't meted out immediately for any infractions it is eventually meted out and in spades at times. A jalapeano coated buttplug isn't a lot of fun (but a quick trip with her to the bathrrom and its all in...even if vanilla people are in the house, she may be uncomfortable but so what) and his slut get right stick makes me cringe just typing about it. Ive made inadvertently or otherwise made mistakes in these regards at tijmes and I learned I have too keep in mind the fine line between being spirited and playful when appropriate and being a childish willful brat.
And all this communication doesn't necessarily need to take place in some kind of time out.
It really helped that my owner sat me down once while punishing me and made me answer as to whether or not I thought it was right to "play" in front of those who are not part of our lifestyle...IE children, relatives etc.
Sounds like she could benefit from the same.
You cant be the only one who is too put forth an effort to make it work...she has an equal part to play in the power exchange and has to remain adult enough to know when and where play time and playful challenging of your authority is and is not acceptable.