Anyone has a MIL like mine?

Not sure if this is common but I have always imagined MILs to be always hovering around their grand children? Want to care for them, watch them, play with them etc. But my MIL does not seem interested at all? Not even want to push the stroller... Only sees her grandson from afar, keeping a distance? Only FIL interested, always hovering over grandson, watching him, playing and carrying him...