Yes, you guessed it!! Beautiful Carrie Anne Moss qualifies for the square jaw club!

You can see in these pics that her jaw is particularly elongated with a nice A grade chin. Face structure is not particularly wide. The distinctive feature of her jaw is the length.
Jaw angle is of B- grade... not super square but still square enough to project and make visible the jawline.

What I particularly like about her is the lower lips / chin structure, so typical of women with well developed mandible. If you look to the woman in the header image of this site, you will notice some similarities in the chin.