"I'll organize your friends to make dinners, drive car pools, shop, etc. — whatever would be helpful."
"I know this is difficult for you, but please know I will do all I can to support you."
"I'm so sorry you have to go through this, but I'm here to help in any way."
"Would you like to tell me more about it?"
"You'll be fine."
"You poor thing."
"I know how you feel."
"I know someone who died from that."
"Call me if you need anything."
"Will you be OK financially since you won't be able to work?"
"I think you should _____________________________ ."
As for timing…
Many friends and family members rush to offer support upon hearing news of a cancer diagnosis — but then the calls subside, even as the cancer treatment stretches on. Stay connected for the long haul, checking in with periodic phone calls or emails to see how she's doing or just to talk about something normal.