If she randomly pops up anywhere near Mako, Asami will boot her out so fast it'll look like a shooting star.

Asami and Mako will have to deal with Xano and Xana before anyone else and I'm sure Mako won't approve of what they're doing to her, it's just a matter of when Asami can see they're just using her for their own cause. Lin and Tenzin will have to work for their happiness but it is possible. I still think it might be possible for Asami to maybe accidentally expose them to something that takes some years off. Or if Tenzin and Lin do more digging and pursue Xano and Xana and there's some explosion, that could also be how things change for them.