well, worst case, threaten to kill any elf that comes to take her. How many of them are they willing to lose just to get back one girl none of them like? Absurd that they would try to force her to marry him as well since he is such a slime ball... If they are going to try for forced marriage and by extension, most likely rape... they should at least pick a decent guy, even if hes already married, having two wives would be better then marrying that other guy...
Though no matter the case, i dont see her staying or marrying that guy. will be interesting to see what happens. id really like to see some death threats though.