I have spent the last 13 months being treated (successfully!) for breast cancer - trying to think of what I found most useful, you and your mum could try the following?
Websites
breastcancernow - their site is really clear and explains all aspects of the disease, treatment, psychological aspects, etc.
TickingOffBreastCancer Written by another lady who’s been through it, lots of good practical advice here and checklists, including one for what to take to hospital. She has also written a book which is a good read and might be a good gift?
Also there are very friendly and welcoming threads in the health section here on mumsnet both for women with cancer and for their relatives/friends, there is lots of good support and practical experience on there. I know I found it invaluable being able to ask questions or get support any time if I was having a bit of a wobble. Let me know if you can’t find them and I’ll dig out the links.
Things that might make your mum more comfortable if she hasn’t got them already:
For hospital - good ear plugs and/or noise blocking headphones, and an eye mask.
Post lumpectomy - a little v-shaped under arm pillow was really helpful in cushioning the sore bits. I got mine from Etsy but there are loads out there. Like this postsurgerypillow
Also a big v shaped pillow or something to support her at night post surgery. I got one of those huge wrap around pillows designed for pregnancy which was great as it meant I couldn’t accidentally roll onto the sore side in the night and also both DP and I slept better knowing he couldn’t accidentally elbow me!
The hospital will probably have already told her to get a non wired front fastening bra.
Things people did for me I particularly appreciated:
Every day my parents have sent me either a postcard (pre lockdown) or an email just with silly jokes and pictures to let me know they are thinking about me. I found this easier than lots of calls, although of course they called me too, as especially when I was having chemo it was nice not feeling obliged to reply at once or to talk or be perky when I just wasn’t feeling up to it. But you know your mum and what she likes best.
DP’s parents sent me flowers every couple of weeks which was lovely too.
DP’s brother and his wife sent us a bundle of meals from Cook! that were really great when I wasn’t up to cooking, they all cook straight from frozen so were really easy, and much better nutritionally than standard ready meals.
Trying to think what else. I got through a lot of audiobooks on audible, and we have Alexa / google home so I could just ask it to play me my book, without moving! Also very good when I had trouble sleeping.
Between surgery recovery and radiotherapy she will likely only be able to take showers not baths, but very gentle, hypoallergenic toiletries are good. Before during and after radiotherapy she will need to apply a lot of hypoallergenic moisturising creams and aloe vera but depending where she’s being treated the hospital may provide some or all of that.
You asked what phrases to avoid. I think sometimes people worry too much about saying the right or wrong thing, and end up saying nothing, which is worse than either! I did prefer it when people talked about the cancer head on and didn’t try and avoid the topic, or worse avoid me. The phrases quite a few patients are uncomfortable with are things about “fighting” the cancer “battle” as though people with less good outcomes somehow just didn’t try hard enough. I’m sure you wouldn’t be like the person who told me that if I’d only been vegan like her I’d never have got cancer...