Dearest plus-sized ladyfriends:

I am working on a gift at the moment, and I don't have the luxury of obtaining sizing information. Therefore, I ask my LJ braintrust, which includes many fabulous curvy ladies.

Where does a necklace comfortably fall on you if it's supposed to rest just below the collarbone? My guess would be 18"-- but I could be way off here. If you could let me know in comments (which are screened) it would be very helpful to me. Thank you!