Kinda sorta not really. She's a great leader and a great sub, but there's never much of a point of running two of them unless you really want one of the not-Awoken versions of her (and honestly, outside of niche type-necessity situations, why would you, because Awoken I&I is superior in pretty much every way).
I guess you can run two and get a double dose of damage boost and 4 skill bind resists? But that's pretty unnecessary.
If I sell my GRonia, which I have not much reason to use, dupe Blonia, dupe ROdin, and dupe Kaede, I can afford a second Xiang Mei. But do I really want to do that....?