two female boxers with aggressive behavior

Question
I have two female boxers 5 years and 8 months old. We took in the 8 month old when she was about 5 months. Everything went fine. No problems. The two boxers shared food, toys, bones, and we also crate them together. Just about a month ago the 8 month old started attacking the older boxer for no obvious reason we can find. She walks around her, taunts her, growls at her. Of course we figured it her showing who's on top but recently they have got into some serious dogs fights thar would happen in a split second. It wasn't over food, or toys, or anything. Just happens for no reason. I'm concerned because I have a small child and one on the way and I'm afalraid that they will break out in one of there fights while he is around them, I don't want him bite. My husband was bit firming a breakup from them. They don't do it all the time, they lay with each other and seem loving, then just bam out of nowhere we are breaking up really ugly scary fights. Any suggestions?  We need help, I don't want to have to regime one of them, but I need my family safe.

Answer
The 8 month old is beginning to show an "alpha" side and competing to become the "alpha."

This is normal with 2 or more and a family which is considered a "pack" with them- yes, you and the family are part of the pack.

The oldest has been the only dog and the alpha of the family/pack. Now, you have the younger one added and all was okay until the younger challenged for the "alpha" position in the pack. In nature, they challenge and if they win, they become the alpha.

The issue will be to modify the younger female's behavior and to get her to accept that the oldest is the alpha. That the age of the oldest has proven to be alpha prior to the pack, and that the oldest deserves the respect as alpha and not to be challenged.

I suggest buying a loud whistle.

When the youngest shows "signs" of the early beginning of aggression; blow the whistle, verbally reprimand her with a one to two word command of reprimand which will divert her mental state off the immediate mindset of aggression, and leash her, take her to a time-out place that you designate. It could be another crate (you will have to purchase a different crate than the one currently being used) to separate and teach her not to misbehave. Crate her for 3-5 minutes and let her out.

Everyone (you and husband) must do this faithfully and consistently. No variation, no skipping.