Why'd you tell her

Ditch that friend, and you should've said something in the meeting when she took credit.

"close friend"

When people do this, the best thing you can do is to cut them off, tell the rest of their (your) plan, and finally show proof to your peers and boss that its your plan.

You have to step up to the plate. "Don't forget, when I told you about this earlier, I said we should also xxxx. I didn't just come up with the idea to WWW, YYY, and ZZZ. XXX was important, too." Flat-out call them on it, immediately and sweetly. Bosses need to know who actually can be relied on and who is not a team player at all. :(

I hope OP responds with an update soon because those kind of people piss me off. Dx

With friends like that...

Thats why you keep ya mouth shut ...i would shot her ....jk

That's not a close friend, that's a bitch. Now you know who she really is..

Unless you told her all the nitty gritty details, you still know how to really make it work. She may very well end up looking like a fool when asked for such intimate details. Make sure to tell your boss all of the FANTASTIC ways you can improve on the idea. After all, you've had the most time to think about it.