Hope you're doing ok.
Talk to her boyfriend about getting in touch with the friend, he'll have a better idea than me.
Athough, I think her bf may need support. Though, I don't know if he would say it directly because I don't know him. Support could be stuff like chatting for a bit longer than usual (if you think he needs to chat longer) or meeting with him socially.
As regards the friend, make sure that she's ok with you knowing about the cancer. I remember reading that soft things (fluffy soft bathrobes) are good for those in kimotherapy, the skin is sensitive (I don't know how you can use this info but I'm sure that it can be used somehow).