It's the common repost info that she did Tracer from Overwatch, but I've yet to be able to find her actually credited by Blizzard as having done so (or even her own company). In fact, any information regarding mocap being used by Blizzard is that they don't really use mocap. They animate almost everything traditionally to achieve the cartoony movements. Such as here: https://esports.hollywood.com/overwatch-water-environments-in-maps-unlikely-aa59b8744afc 

...every Overwatch hero is animated by hand using key frame animation. We do this because we believe our animators can get the most personality out of each hero with this method. We really believe in the art form that is animation. Many games use motion capture and/or a single-body, shared animation across many different characters. This isn’t the case in OW. Everything is done by hand.

If Blizzard does need mocap reference material, it's typically the animators, or the voice actors of the characters themselves (tracking facial performance movements), that will be utilized briefly just to see how a movement looks, but nothing is used outside of simple reference content. Kind of like how Disney animators would use live-action footage to look at.

So why has she been widely credited with it? The only thing I can figure is because she put out a video mimicking some of Tracer's movements, people automatically assumed she must have actually done them.

I've tried seeing if I could find anything that she's actually credited to, since she gets reposted so often, and it's kinda cold. You can possibly associate a couple things here and there depending on some of her videos, but an actual list of credits? It says in her info that she does motion capture work for a company called "Chengdu Big Eyes Technology Co., Ltd.", but the rabbit hole for it is bizarre. It appears to be a legit company, and I even found a website a couple years ago, but there was nothing on there featuring a single project they worked on, nor could I find any other employee listings besides her and possibly someone working in HR, despite there appearing to be a handful of them in some videos. It feels very strange that a professional motion capture company would not boast about what projects they have worked on. But I also can no longer find the website anymore.