I would imagine that my friend is trying to say "My work is very difficult, but other than that I'm fine!",
But for me it feels like it's missing an adjective like 難しい.
I imagine it should be
My friend is Japanese, so I would guess that either
- 仕事は大変 is assumed to mean "Work is very difficult", or
- She forgot to include an adjective
Am I wrong in understanding, or did she just forget an adjective?