You know that torment. It shows itself in many guises, but the result is the same: our suffering. When we are highjacked we act out patterns and behaviors that don't meet our conscious needs or intentions. This happens because we are fighting a powerful unconscious commitment that is causing us to repeat familiar patters even when it feels so bad. These aren't small committments, these are the biggies: an unconscious commitments to avoid conflict at all costs, for instance. We formed beliefs around these behaviors (Like saying NO to requests for our time makes us selfish or unlovable, or makes other people vulnerable) in order to keep us safe and mitigate the threats we perceived in our family of origin primarily, and at the cost of our own met needs. Sorry to say, that wiring is still intact. The good news is that as crappy as it feels to spin in that confusion and pain - it's a gift. If we didn't feel such discomfort, we would't know that we are READY (and POSSIBLY WILLING) to do the hard work of change. When we are unconscious but only moderately miserable, well then, we'll just remain so. But if you find yourself stomping around, casting dispersions, raging or sobbing, don't blame your parts - you've won the jackpot! Thank them for making enough noise to get your attention.
Take care of them. After all, they developed as parts of a much younger you, when you had no control about your own survival or anyone else's.
What she needs is a gentle guide to walk her back from the edge. (A trained coach or therapist, or skilled listener)
She also needs some language tools. (I personally can't ever get enough boundary language practice!)
And then she needs to practice saying the words that will help train her brain to trust that YOU (and ME), the ADULT woman in the room, can take care of business. (Like, "I got this my sweet, you can go to the mall now).
Takeaway: We all get hijacked by unconscious patterns and thoughts that cause us great turmoil. What we resist persists, right? So get curious about what that younger part thinks she is protecting you from. Reassure her that you - wise woman - are here and then practice using the language that will free her from her vigilance and give her a much needed break.