Understanding a language and being able to hold a convo in it is very different
And maybe she actually can speak english but is not comfy/confident enough to do so in a public environment in a stream infront of thousands of people.
It's not rare to have very bad English in EMEA teams. As long as you understand the rest is just set callouts. Impressive tho cause one of her main strengths was also supposed to be the calling since she used to IGL