Answer:
They could be afraid of what they may be doing. They also could be worried on how they are so addicted to the phones. (Which is not so healthy)
Step-by-step explanation:
Let's say a teenage girl is texting and starts to laugh. The mother is obviously going to wonder on what she is laughing about.
A mother could be worried on how long she has been on the phone and the daily times she checks it.
I really hope this is helpful :]