Thanks for the additional information added to your answer in the comments... If I understand correctly, you need a mobile page to accompany your web page.
It is unfortunate that this is the case. These days, most implementations can use just the one page to accomplish both purposes due to smart-phone browser capability and responsive frameworks such as Twitter Bootstrap etc.
If the mobile pages can be served from a subdomain or a subfolder (i.e. mobile.example.com or www.example.com/mobile) this would be a perfect use case for BluePrinting. You can create a child Publication for mobile from your web Publication (and, if you have a design Publication, a child Publication from that for mobile design) then localise your PageA template to product the required alternate output. This means that your author only has to create and manage one page but they also gain the advantage of being able to localise it. To publish, they can publish from the main web publication and use the advanced tab to also publish in child publications, or you can automate that using an Event Handler.