HAC
I have just looked at the CX cabin baggage guide, issued pre clear plastic bag era, and you are allowed an umbrella.
However, a Chinese umbrella has those nice bamboo spokes, poking of eye out for the use of, and more rigid than the normal metal spokes. I do not know in the current climate whether you could hand carry such a potential weapon or not.
I suppose you could pack it in a fishing rod case and mark it fragile, ha ha.
Incidentally, you may also carry crutches on board, which I suppose you might need if Mrs HAC does not get her umbrella.
Good luck