Ariel was relieved when Maleficent said she would indeed again find her heart. Ariel did believe in hope, as well as strongly in the presence of true love. She was taught by the stories that true love existed. That when a mermaid found it and experienced the first kiss of true love, she would in fact become a creature with a true soul and a purpose. That instead of mingling with the sea once her life was over, the mermaid would become a daughter of the air and ascend.
True love would bring that and she couldn't let herself be deterred by anything now that Maleficent had sparked within her a second chance at finding it.
Ariel glanced down at her legs for a moment, as if studying the pair of appendages, before lifting her head up again. "There is the pain..." Ariel replied, motioning to her legs. "Penance for the task of splitting a fin. At times it hurts to walk, but I've learned to manage it."