Having a gape that big for a beginner is not possible without using a rather large toy for sometime. I could see a baseball bat in her very near future.
I think that it is pretty safe to assume that, even if this is her first time doing anal on video, she isn't exactly a "beginner" ...
The mosaic masking in most of her videos, including this one, doesn't cover her hole and it certainly looks to me as if it has been getting plenty of action for a long time.
Have to say that I am not a great fan of the "gaping hole" look - it's OK for a few seconds after the guy pulls out but, after that, I like to see it close up nice and tight again ...