Just to clarify, in case there's any confusion. Ember and Emilia are not chained down or bound to anything in the arena itself. They are specifically chained to each other side by side, being shackled wrist to wrist and ankle to ankle (only one leg and one arm are connected to each other). Unless she lacks the physical strength to drag Emilia's arm up with her there is nothing stopping Ember from reaching her hand out as she had attempted.