Zebra finch pair fighting alot?

My mother recived a pair of zebra finch pair. As my grandmother passed they where her birds. They are about 3 years old.well they have been settled in for about a month.latley they have been fighting no stop. My mom leaves the cage door opens and the other pushes the other one out? Aslo the cage is about 19inch in L, 11 inch wide, 16 inch tall. I could be wrong though as i can't messure it properly as i used a iphone to compair.

Zebra finch are not the kind of birds you let out of the cage - they are too small and nervous. Tell your mom to leave them in the cage, make sure they have what they need and just ignore them - they will settle down. It could be the new environment, new smells, etc. - they may just need more time to adjust and they are naturally such nervous little birds, it takes them even longer to settle down.

I think you should get a much bigger cage, they need a flight cage, which means they need to fly back and forth, thats why they are fighting, they most likely were fighting before you got them, they do not need to go out of the cage, they have no room in that cage you have them in