Hi Expat Daughter
Welcome to the Breast Cancer Care forum. It sounds like you're doing all you can to be prepared. While you're waiting for replies from other forum members, you might find it useful to read this booklet about breast operations and recovery. Although aimed at people who are having surgery themselves, it contains lots of information about what to expect, so it might be helpful to you too.
When you are back in the UK, if you find you (or your mum) needs to talk, our helpline is there for both of you - 0808 800 6000.