Boxers are boisterous and full on as a breed.
The pup is just starting to come into the 'kevin' or unruly teenage phase.
Boxers tend not to mentally mature until they are at least 18 months-2years old.
Even then they don't really grow up.
I still have a bitch who will be 8yo this May and she's still as nutty as ever, full on etc etc.
My one big mistake with her was to concentrate on her showing career and 'forget' the basic
training as obedience classes. Boy have I paid the penalty ever since!!
Her daughter who did go to both ringcraft and obedience is a joy to live with, her
mother is a pain in the bum (even though I still love her) and isn't such an easy dog to live with.
My youngest dog is yet to start formal obedience classes but I have trained her and she is also
easier.
Whatever your friend puts in now into good quality obedience training classes she will reap the rewards
as the dog grows up.

Unfortunately most people when having Boxers as pups don't realise that without obedience training
they grow up into unruly adults that are strong willed and by that stage they then pass them onto
Rescue as they can no longer cope

:rolleyes:
One thing to impart to her perseverance and consistency is the key - Boxers are highly intelligent (despite
being called the clown of the canine world) and if you learn what 'buttons to press' you can have a
highly trained companion - Boxers can be stubborn but when they want to do it they are wonderful :D