She could also have a handful of bots following her that get deleted which would result in less followers every so often.
Anyway, her total is still quite a bit higher compared to a year ago. She should be hitting a million sometime next year if she keeps this up imo.
Also, she has 837,800 right now so I'm sure there's nothing to worry about as far as people 'not following her' anymore because for every handful that unfollows her, more than enough click that follow button to replenish those 'lost' followers.
If you want to see how her followers have increased since joining 2 years ago... she's never really lost followers. If anything, every few days, she gains at least a thousand or so followers.