Attainable Goals?

As everyone knows, I've been in quite a rut with running since the Disney Marathon.  I'm back up to about 3 miles now, and I'm toying with the idea of signing up for a long run on April 10th - the Iron Girl 15k. 

Here's what scares me:

• It's NINE miles.  That's a lifetime away from 3 miles! 
• Do I WANT  to run that far again?  
• CAN I run that far again so soon?    

I'm tempted to sign up for it and give it my best shot...what' the worst that can happen?  I know the answer to that - I'd walk more than I wanted to then be pissed at myself for weeks.  Best case scenario?  I FINISH and get myself a fun finishers medal and a cute little plush Duck! 

I may have just talked myself into doing this!