play fighting always looks rougher then it is. dogs are a lot tougher then we are so what makes us cringe is nothing to them. sounds to me like they are both enjoying themselves and bramble seems to be able to hold her own. if either of them goes too far they will let the other know. let them get on with it, unless they become a danger to people in the household. lol. we have to sit with our feet up out the way when our two start and even then your not safe.