My daughter and her friends show each other kindness by regularly WhatsApp each other to ask questions about lessons and homework.
I think this is a kindness that they want to help each other out. Things like do they need certain types of PE kit or is homework due in on a certain day.
The homework thing in particular is interesting because their homework is set on Google Classrooms so they could look it up but they usually choose to message each other directly to ask instead.
Do you notice this with your children?