Elizabeth's wager (3)
I believe the answer is:
I believe this is a double definition.
'elizabeth's' is the first definition.
(I've seen this in other clues)
'wager' is the second definition.
(Other definitions for bet that I've seen before include "Wager, speculate" , "Wager, back" , "22 across will accept one" , "Money risked on a gamble" , "Wager, or the sum waged" .)