T.S.
Had the same problem. Mine did it more often when they were tired. Sometimes they didn't even notice they were doing it! None of that other stuff worked for us either.
Try making a rule that she can only suck them on her bed. Whenever she's sucking them, send her there, even if she says she's "done". (set a timer for 5-10 minutes in that case).
Alternately, until the gets the "hang" of the new rule, remind her of the rule and give her the choice. Stay "out" and do whatever else she wants (within reason) or go to her bed to suck them. Eventually she'll lose interest.
Either way, don't get upset or excited about it, just very matter of factly send her off. "That's just where we do that".
Hope it helps. Good luck.