Long-distance friend going through a hard time

My friend's dad has cancer that is likely going to be an incredibly long battle, or will end poorly. Naturally, my friend is struggling with their dad going in and out of the hospital regularly. They are also struggling with work and might quit (I suspect this also has to do with the added stress from their father, but idk I'm not a psychologist.)

I am not sure what I can do to help. They don't know if they want to talk, or want space, or what they want, and neither do I. How might I help them at this time? What can I do?