I had two followers, one wondered off many moons ago, so long ago that I cannot remember her name or where she comes from.

When I met Zora Fair-child, I was so enamored with her voice that I want her to be my follower, in order to even get an dialogue option to recruit her, I had to dismiss the follower whose whereabouts I still knew, (At the Children's home looking after the kids), Thing is, though I now get a dialogue option to recruit Zora, she must be the jealous type as she wont follow me whilst I still have the missing follower somewhere?

So, How do I find out who and where my missing follower is please?

clearly you are a PC user so there must be a console command to move to your follower or to move your follower to you.

Easiest way is to use the http://elderscrolls.wikia.com/wiki/Console_Commands_%28Skyrim%29 :

set playerfollowercount to 0

I thought I would need the ID of the follower to use the console command, but this has worked a treat, thank you.

If you use mods e.g AFT then you can use a summon follower spell or if your follower has an active quest in your journal then just activate the quest and you'll find your follower via a quest marker on the game map.