Hiya lovely, I had an appointment on the 23rd at the breast clinic, as I had a palpable lump. They did an ultrasound (too young for mammogram), and nothing showed at all, no cyst, not fatty tissue, no glandular, nothing. It just looked normal.three days later they had me in again for a core biopsy, and they said they didn't know what it was, but the biopsies floated, which is what fatty tissue does., so fingers crossed. Like your mum, I was told two weeks, then the very next day a letter arrived for the appointment, which is actually on the 11th Feb. Mine also said I can take a relative for the results. I am also booked to see an onco plastic surgeon. A friend of a friend works there, and she aid its pretty standard to see that type of consultant, and that it's also pretty standard to be allowed to take someone with you just in case the news isn't the best.

I was also told it may be a cyst, however it's my understanding that if it was a cyst, there would be some sort of fluid in there, pus etc, and also a cyst would have shown on my ultrasound. 

Most breast lumps are non cancerous , so sending all the good vibes to your mum that she is cancer free