Hey desire, welcome to the forum. At age 7 she is border line mature. males tend to be effected more with aggressive issue at maturity than hens. The best cure is early socialization where they are exposed to lots of people and aren;t the "one person" bird that many zons are famous for. Of course with a rehomed bird ,that is out of your hands at this point. Could it still be a good family pet ? Yes but i would pick a rehomed bird who "picks you". Visit lots of birds and find one who will allow many different people to handle it and shows a lot of interest in you. When you bring it home it may have some issues with changing enviroment but the bird is basically well socialized, it should adjust fairly quickly. Aggression issues caused by hormonal changes during breeding season are usually short lived and don;t carry over for as many years with a well socialized bird.Of course when bring home a mature rehome and change his "flock" that;s your big chance to socialize them better with help from all of your family members.When ever they start to adjust and show interest in one person that one person should back off a bit and let someone else step up and fill that niche for awhile. I would say that if the bird your interested in seems to accept you, then with the help you can find here, you can work though many aggression issues. Hormonal aggression issue can be minimized with diet and environmental changes. Socialization is however the real key. Birds that mate for life tend to form strong bonds with their owners ,which makes them so great as pets, but nature teaches them to defend that mate when in breeding season, your challenge is to over come that natural instinct with good socialization, I have several rehomes who were mature when they came to live with us but have learned to be very comfortable with many people and don;t have biting or aggression issues with most people. There are no guarantees but with a handlable bird , your chances should be good. IMO more will depend on your dedication than the birds nature.