Oh boy, I don't think people realize how upsetting it is for me to see these kind of posts. I apologize in advance for my bluntness, but these situations really get to me.

Tim, take that poor dog to a rescue! Don't sell her to your brother in law, take her streight to a rescue. If you care about her so much, then you will be able to turn down $600 to make sure she ends up in a home that has been specially screened to make sure that the family that adopts her can care for her forever. And if you absolutely must sell her to your brother in law, spay her first.

I really don't understand why you got her. You knew boxers needed alot of work and you also knew you didn't have the time. And do you honestly think that a dog that is kept isolated to the backyard with no training, not nearly enough interaction and stimulation and no exercise is going to protect your family!? Your doing the bare minimum for her, treating her like she's nothing more than a dog or an animal to have, why should she do anything for you? If you keep this dog, she'll probably end up aggressive and you won't even be able to trust her with your children none the less expect her to protect them.