So in 8 years it does not sound like she has had much training at all and therein lies a big part of the issue. Without regular training, they run on their instincts of being a dog with nothing to tell them the behavior is not wanted.
There are devices that may help stop this. There are collars that spray water or citronella when the dog barks and there is a barker breaker you can set up inside the house and they make them for the outside as well. A word of caution, the humans can also hear the high pitched sound, but if it works for your dog, she will be corrected even when you are not at home and the dog learns to only bark two or three times before the device goes off.
The other thing you can do is teach the dog a couple of commands.
In order for a dog to understand what quiet means, you have to teach that. Because she is a barker, you would teach speak first, then teach quiet. When she barks use the quiet command, but you can't use that until the command is taught.
You can also teach her the leave it command. which is useful when you are on walks. A good heel and leave it command can stop the dog from barking at other animals or people even cars. Leave it , when taught to 100%, should mean to the dog, leave everything you have your mind on and put your attention back on me for the next command. Then if walking you would give the heel command. If you were home and the dog barked at the window or at someone coming to the door, the leave it command would mean the same. For these instances you may want to teach him to go to his bed when someone is at the door.
When you train leave it , use a variety of items.
leave it Video https://www.youtube.com/watch?v=Y8oaB7MAJnI
Barker breaker https://www.walmart.com/ip/Amtek-BB1-Original-Barker-Breaker-All-Purpose-Pet-Trainer/322070266
speak and quiet https://www.clickertraining.com/node/185