It is very possible that she is in pain. When they are in pain it can definitely change her personality so a vet visit is probably a good idea.
Did anything happen yesterday or last night that would have upset her or stressed her out? Have you fussed at her or popped her? Anything change within your home or yard?
Did anything happen yesterday or last night that would have upset her or stressed her out? Have you fussed at her or popped her? Anything change within your home or yard?