If she just started, she might be nervous and talking more because of that. I’d just tell her that your Mom likes things fairly quiet and is not very talkative. That too much talking makes her uncomfortable, tires her out, overstimulates her, etc. Make your comments about your Mom and her preferences and needs, rather than about the caregiver’s behavior. That will make the point without her feeling like you are criticizing her personally. There are ways to say “My Mom doesn’t like a lot of talking” without saying “You talk too much and it bugs my Mom.”