Aging preteen to teen

I need help with how to age my preteen to teen. I am over level 20 but don't have Osiris in my town to do that quest, so what prerequisite do I need to do? ...... I got a pop up window when I clicked on have birthday on my preteen that reads:

"To age a preteen Sim to be a teen you must first complete the teenagers quest which is attained at level 18. Note: if you have reached level 18 but can't see the teenagers quest yet then there are other quests you need to finish first"

Well what are these quests I need to do?! I wish I could find a clear guide to all quests for this game, like some chronological order listing.

Have you checked our guide out / It is pretty comprehensive, maybe a page there will be able to help you...

Here is a link to our teenagers guide page>
http://www.supercheats.com/the-sims-freeplay/walkthrough/teenagers

I completed this myself recently, but sorry, I cannot remember exactly the pre-reqs, I think it just appeared after I completed other quests. Maybe there are some outstanding quests in the park that you have not completed yet.

Hmm ok, well I'm working on the nanny quest right now. Otherwise all that I have currently in my park is the construction worker and the guy with a house icon above him.