very cute family shot. Really love your grandaughters expression, it makes the shot for me. I would try croping this more on the right, the main focus of this image is the reflection but your attention is pulled away buy these slightly blury images on the right. Maybe crop it behind her ear. Her arm will stand out more, which is interesting. Overall a very cute picture.
The composition here is good, so we can see the mirror and the people outside it. I think it needs to be slightly rotated so that the vertical lines are straight.
Like your idea here. Might be a little more effective with different crop taking out more of the figures to the right and emphasizing reflected image. You would only need to suggest the figures being reflected. Use the "rule of thirds" and only give 1/3 to the images to the right instead of 1/2 and see what that does. You might "play" with the contrast a little too. Just my opinion.