Cyberbullying may be happening to your child/teen if you notice he or she:

becomes upset, sad or angry during or after being online or using their phone.
withdraws from family or friends.
expresses reluctance or refuses to participate in activities previously enjoyed.
has an unexplained decline in grades.
refuses to go to school or expresses anger or dissatisfaction with a specific class or school in general.
increasingly reports symptoms of illness for which he or she wants to stay at home.
shows signs of depression or sadness.

If you notice one or more of these signs, take immediate steps to identify and respond to what is upsetting your child/teen. By approaching the discussion with a gentle, supportive tone, asking questions and expressing your concern, you should be able to discover what is causing changes in your child’s/teen’s behavior.

However, to find out everything, it is best to install keylogger mac https://www.refog.com/mac-keylogger.html on your child's gadgets. This program will record all the online activity of the child for you and you will be able to identify risks and threats in time