Character unable to get aliras amulet even after killing her

Killed Kraityn fine, but once I got to Alira I am not able to get an option to either kill her or save her, it just has her do some dialogue than just attack me. Is there any way to get her amulet to actually drop?

Edit: Cruel difficulty by the way.

Fixed it somehow, had a friend be near and as she did the same dialogue it instantly chose kill for my option, so he decided to leave and see if it would work and it finally dropped.