If so, which of Jigglypuff's attacks can meteor smash?
Sadly, it doesn't. None of its moves have a meteor smash or a meteor effect.
Source: Playing Jigglypuff a lot. And getting stupid Rest kills. Sour spot F-air into Rest works, surprisingly.
Yes. Jigglypuff can perform a Meteor smash with Spinphony, but without using custom moves, her Down Arial can do a trapping meteor smash.
It is not easy, but do-able.