I have noticed when working at home that my nanny ALWAYS has her mobile with her, no matter what they are doing; and I've heard the text noise go - so its sometimes switched on - or was on that occasion.
Now when I'm at work, my phone is on silent - although I have it close by just in case DS is ill and she needs to ring me. Don't get me wrong, I am happy for her to have her mobile at work so she can get hold of me. But often I am in the same house, working ...and I am concerned that she may be texting when she's supposed to be entertaining the DS! She is supposed to be working after all.
She has no children, her family live abroad so not sure if she has any elderly relatives who are at death's door etc...and that would require her to have her phone with her at all times.
Apart from being 10 mins late EVERY morning (which I am dealing with separately) we are happy with her and DS seems happy.
What would you do? I am not great at confrontation and personality wise I feel she would get angry and defensive if I asked her about it... I don't want to spy on her to see if she is using the phone or not!