No idea how good she is but by going duo heal vs her im right now 11 or 12 - 0 vs her. And i aint joking. Im dia 3 and did not lose a single match vs her when i went 2 heal comp.
Im actualy counting how long till i lose. Man only 1 fight was close.
We let enemy pick her 
when we ban, that is how week she is vs ana or WM + reghar or khara combo. NOT A SINGLE LOSS.
Here is the post about how we did it.
https://us.forums.blizzard.com/en/heroes/t/quira-aint-as-good-as-ppl-think/25506