Pregnant and have 2 dogs

I have a maltese and a yorkie who are both 9 years old. They always have been very loving and ever had any type of aggression.

Ive recently noticed my maltese has gotten aggressive with other dogs. Like she basically tries to take their faces off! its really weird. She doesn't do it with dogs she's familiar with. Just new ones who happen to walk by. Could it be with age she's getting cranky or does it have something to do with me being pregnant? Its happened a few times already and I'm terribly upset for the other dog and their owners. She doesn't get nasty with ppl at all. ITs just other dogs.

Any advice or suggestions would be great. I don't want her to be known as "that dog".

Pregnant and have 2 dogs

My dog became very protective when I became pregnant. I worked with a dog trainer to address the behavior and prepare for my daughter's arrival. My dog did well when we brought the baby home- so far he is doing well so the training was worth it.