Yuki, having wiped out several AI controlled Hi Mocks, just floated there, deactivated Beam Sabers in hand, using the wreckage to mask the presence of her Gunpla. This was a Battle Royal, and they probably had a set number they where looking for, with that in mind she decided to simply wait it out and watch every one else fight and move on that way. 

Plus this gave her a prime opportunity to see what every one else had cooked up, and really, she was more interested in what every one else had come up with more then actually fighting.