Sounds like a typical day at a dog park. Sorry, it's just that this stuff happens all the time at dog parks which is why I avoid them. In this case you had two owners that were not neglectful and watching and a dog still got hurt. Your dog is old enough that she will not get screwed up in any way from this, she is just a dominant female. When she comes across other dominant females she needs to be controlled (on leash). Please make sure you do not get her around young females, as she will do some damage there.