Doesn't sound like she's trying to be the boss to me. Just sounds like she didn't get taught what 'come' is.
And that 'come' is the BEST command in the world, cause being with/near/by/along side me is just about as close to heaven as heaven can be!!!!!!
I start when my pups first come in the house, and don't use the word 'come' at all. I just use their name. And when I say it, and they look at me, I use a clicker to 'mark' the behavior I want (looking at me) and then giving my pup a chunk of chicken/roastbeef/liver/cheese............. Hey, but guess what's happening when they are coming over for their treat? They are 'coming'!!!!
The most important thing now is what many of us mess up when our dogs are outside. Our dog 'comes' and we immediately gather them up with the leash or by the collar and leave the fun whatever they were doing loose. So the dogs learn that when they get near you, the fun is over. If they avoid you they can keep having the joy of freedom.
So what I do when I click/reward my dogs is then LET THEM GO AGAIN. And do the name thing again, click/reward, let them go AGAIN. So the dogs never know which of these is the time I have to leash them up to go home.
You may want to pretend your dog is a 7 week old puppy and retrain the both of you all over again. And this time, all the commands and learning is about fun, teamwork, leadership, and rewards for your dog making the RIGHT choices.
Does your dog tug? A tugging dog is the best of all, cause the reward comes from you and is WITH you.
Dog classes would help, specially positive based ones that would make you the leader and the light in your dog's eye. Someone they WANT to listen to and obey (not someone they are stressed about cause they make think they either 'have' to obey, or that is to be avoided cause (frankly) you may tend to suck the fun times out of their lives (unintentionally, but a fun-sucker none the less.
So I'd back off and start doing some basic reading on leadership (not being the boss, but the natural leader) of a dog. As well as basic positive based training (and I think clicker training breaks it down the best).