I wish I could offer more specific advice.  This is all I have:

Your mum should also stay away from estrogen containing plant foods:  maybe look this up: Nutrition facts .org may have research to share on the topic.

Also BPA (soft plastic in cling film and the lining of tins for instance) should be avoided as these contain estrogens.

Yes HRT has to stop. I would ask to be her next-of-kin with her GP and the hospital doctors (your Mum would ahve to authorise this) and then ask some questions with her or on he rbehalf as to medications that could help with the mood swings. if you use herbs for this, such as chamomile or st Johns Wort you msut tell the doctors due to potential drug interactions.

I would visit her frequently. help with her shopping. Make her a cup of tea and cook meals and that way you can support her in practical ways and also keep an eye on her emotional state. If she wants to cry in private there is very little that you can do really. Jus tbe there for her as muc as you possibly can and ensure she can call on you when she needs you, which she will.

The NHS can be really slow just when it appears they should be acting really fast. i think this is due to a lack of resources. Yes it is common to ahve to wait for an operation. The only waya round this is to pay for her operation to be performed privately. Yes the cancer can spread whilst waiting and so it would be wise to ask the cancer doctor how aggressive the cancer is. radiotherapy is not as taxing as chemotherapy. I would ask if she is going to have both and how aggressively they are going to treat the cancer. The best way to be fully informed is to offer to go with your mother to her appointments. Please rememebr to allow her to fele in control though, no matter how much you may want to speed thigns up and help her. I made this mistake with my mother, who liked to feel in control of everything and yet was too polite to question the doctors. it is a juggling act between gaining the right infomration and being mindful of your mothers' feelings.

i wish you both well and I really hope your Mum recovers. i am sure you will do everythign you can to help her. She is probably just hoping you will offer. Your relationship will change during this time but take it form me, she really needs you.