female boxer really play rough with her brother

Question
have 2 boxers age 2, bother and sister.
both well behaved and good with humans but they play very rough together, i no they are playing but the female is getting very rough with him , pulls his ears and neck till she has him on ground , he had a stich in his ear where she must of bit him ,
he is a lot bigger than her but he never tells her off, she is always ontop of him pulling or biting some part of him.
even worse on walks, i shout at her and tell her off it dont work,tried to destract her with a ball or toy but it dont last long even advise please !!

Answer
Boxers do play roughly; if the other dog isn't getting upset and no one is routinely at the vet then it is just play. Still, rough play can be annoying or upsetting for the humans who have to listen to it all the time!

Basic obedience training for both dogs will be helpful; if they've already had basic training, then just aim for 5-10 minute "refresher" sessions with each dog, at least once a day. When the play gets too rough, recall them both and give them a brief stay at sit or down, just to calm things down a bit. If they don't voluntarily separate when you call them, then (along with working on the recall) go to them and put them in their crates for a few minutes as a "time out" -- don't punish them, yell at them, etc., just calmly and without emotion put them in their crates. Alternatively, you can make the crate a "prize" that they've won -- get very excited and happy and run with them to the crate like it's the greatest thing in the world. If you do this consistently, they will learn that rough play gets them a time out (or a prize they really don't want), and they'll learn to modify their play so that they don't earn that particular response.

You can apply the same basic concept to walking -- turn around and go home as soon as they start playing rough. They'll learn rough play means the walk ends, and so they'll avoid rough play. If you aren't walking them on leashes, you might need to do that for a while -- it might also help to do some walking/loose leash/attention training with each dog individually to reinforce the basics.

Once they start figuring things out, you will notice that they start to play rough and then back off themselves, without any input from you. At that instant praise very heavily, give them some super-yummy treats, etc. -- anything to strongly reinforce the self-control.

Good luck!!