Pregnancy and over protective dog

I'm not sure what to do about my dog anymore she has become so over protective of me that nobody can come around me without her growling and snapping and then lays right next to me or on me. I'm scared she's going to bit one of my kids and she keeps getting into a fight with my other dog who doesn't do anything because she's old. Getting rid of her is not an option because she's a rescue and a huge part of my family and I don't want to put her in her cage all the time.