Hi I'm wondering if someone could give me some tips. We have 2 amazing cockapoo. Half brother and sister and are amazing but in the past couple of days the female has become aggressive when it comes to playing and toys. For example they can be opposite end of the room and for some reason she thinks her brother is going for her toy and will growl before going for him. We are separating her when this happens and we have read that this is common in 6 no th old pups die to the imbalance and development of their hormones. Apart from this they get on so well and sleep fine and generally good with each other it's just this aggression for her when it comes to treats or toys. Can anyone give us some tips?