HI Katiesupportingmum. Great that you are here to help support your mum. The site has lots of really useful advice and the breast nurses can be emailed or rung with any queries (info at bottom). I have children your age so know that they had their own concerns when I was diagnosed. My daughter was able to find stuff out without feeling she had to discuss everything with me and vice versa (probably both trying to keep strong for the other).
Anyway, both you and your mum are welcome and will get support from the people who post.