Two people saying that it was her personal phone does not mean that it was her personal phone.
Maybe there's more info to confirm it to be true, and when I see it, I'll believe it.

And walking this back to my Walmart comparison with yet another example, before Walmart provided everyone with a phone, they encouraged us to download an app to allow us to use our personal phones for work - they called it BYOD. (bring your own device - "device" being Walmart speak for those handheld scanners we used to use)

Could the feds do something similar? Use your personal phone to do "work stuff" using apps?
I don't know, but it's a possibility.