Personally I would say No.
Age 14 is too young to be having chemicals used on them and there is the home care to consider.
Ultimately it comes down to what your insurance company says so give them a ring before accepting the appointment.
My insurance would not cover this for definite.
I know that when 14-16 year olds are on hair & beauty courses Habia, VTCT & City & Guilds all say that you can't use chemicals or hot stuff on them (e.g. lash tint, gel polish, paraffin wax, wax). Areas of the body you can treat are up to the elbow, up to the knee, down to the neck collar only.
Hope this helps but it's an area you need to be sure of and follow exactly what your Insurance company says.
Just some other points for anyone reading - Under 16's cannot have appointments in school hours, parent needs to sign a form declaring any allergies or medical issues for the child and they must stay in the treatment room during the appointment. You have to keep records of your treatments on under 18's five years past them turning the age of 18 in case they decide that they were forced to have the treatment in which case it is child abuse.
Sorry, not a very cheery note so late in the evening but if you follow what your insurance company states to the letter you will have no problem.
If you are questioning yourself on whether you should do a particular treatment on a child and alarm bells are ringing in your head just say no!