So in addition to throwing the gal to jail for life, you condemn a bloodline to extinction as a safety precaution?
There's no guarantee Yuta would ever stop being a murder machine even when running out of targets, mind you. If there were no pure Lornaks left, what would she strike at next?
A more immediate concern would be that she would live in horrible agony for the next few hours, flinging herself against near-lethal phasers and forcefields and whatnot - and obviously, the already demonstrated inability to complete her mission would not be a factor there. When would that
stop? When Chorgan was moved to safety? But Chorgan was already
in safety, guaranteed by Riker's demonstrated firepower, when Yuta basically chose to commit suicide. Making her reverse that choice at a later date would seem to call for pretty extensive mind-wiping...