Shewoman, on Aug 14 2008, 11.05, said:
I don't recall the word "valonqar" ever being used about Dany.
The "valonqar" prophecy in AFFC, p. 541 in US hardback, says "the valonqar"--not, specifically, "your" valonqar. So I don't think the field is limited to Tyrion and Jaime. You KNOW there are more than two people who want to kill Cersei!
You're right about the first bit and mostly right about the second bit. The dude who brings her a dwarf head does say "your valonqar" and is lucky to escape with his life. Coincidence, foreshadowing, I dunno. But every arrow points to Tyrion which is why I think we can conclusively rule him out.
For my half a groat, I'd say Benjen Stark qualifies as a Valonqar with more reason to want to strangle her than anyone short of Tyrion and Jaime. But if Valonqar happens to be gender neutral, Arya Stark is your man!