Hormone therapy won't help mlc. If she is in mlc, or having a crisis over entering her second adulthood, your ride on the roller coaster from hell may just be starting. It can "easily" take a person in crisis two years or more to complete the process of this transition.
They will try everything within their grasp to run from the inevitable. They will blame you and others for not wanting them to be 17 again. Expect other shopping, for younger clothes, or whatever they think will make them happy. If it is only a fridge, you are lucky so far. At least you will get to use the fridge. Many have had to pay for Harleys, cars, and other toys to be used in pursuit of fun ... with OP.
Be her rock. Be your rock. Focus on your faith. Give her space.
Be prepared for her to re-write the history of you life and your M. If it is mlc, expect to hear that M to you was a mistake and she never really loved you. If she feels you are holding her from finding her joy, she will try to destroy you to be free.
This may not be the support you hoped to find on a mlc forum, but mlc is not about hormones and it can't be "fixed". The reality of mlc is you are only an observer, unless you become a victim of her crisis. She must go through a life changing process and the harder she fights it, the worse it will be and the longer it will take.
Your best hope for a non-catostrophic outcome in less that two to five years, is for her to complete this journey within herself without fighting it.
Look for some archived posts at the top of this forum for more on mlc.