Mera deliberately dragged her feet when it came to following Yifa.  She'd gotten the bit about going 'someplace fun' and decided to let their roles play it out and so on and so forth.  She was out the door half a minute after Yifa had gone, and pretty soon she was following - though at a bit of a distance - the 'wayward princess' through the streets of Whitewall.  She would keep her distance for the time being, and wait to impose herself at a dramatically appropriate, or inappropriate, moment.