Watch her body language around the people she growls/barks at. Has anything changed in the household? Does she seem nervous or scared or uneasy at all? An aggressive dog is usually a scared dog. Is she in heat or spayed? There are a lot of compnents that can go into a dog suddenly becoming aggressive. It’s defintely something that can be fixed. A wonderful group that I go to often is “The Dumb Friends League”. They are great with answering questions and helping with behavior problems.
Good luck with her, I hope you get everything figured out.