I would teach her quiet only, if she is a barker already I wouldn't try putting it on commnad b/c she might associate barking with treats and do it even more. I would teach her quiet so you can tell her to be quiet when she is barking and you don't want her to bark.
Teaching quiet is pretty simple. When she barks, say quiet.... the minute she stops, c/t or treat only , praise, play tug/ throw a ball... whatever your reward. You need to be ready and set her up to succeed. and try to keep you emotions down, don't get upset, just wait. It will take some time but she will learn that quiet gets her treats and will refocus her attention on you.
Good luck!!