If there is one thing every professional hates, it is clients showing patterns of being late, having uninvited people coming and going, and continually having distractions in lessons/appointments!

I believe I speak for all other professionals when I say the following:
1) You have hired us as professionals to help you. Please be respectful of our time and expertise. Be ready at the designated time. 
2) All distractions turned off or put away, and all participants seated.
3) Children may attend lessons if they are mature enough to receive instruction and participate in the training.
4) Organising strangers and friends to come around, not invited to participate in the training, is unacceptable.

I can only speak for myself, I believe that you should have flexibility with taking accountability!