She supported her sister and assured him that she wanted to marry him. What ever the reason Dharmi is missing, its still Mukhi's honor at stake. And that is important to Aru too as if she could walk away from all those alliance meeting when those folks were not being respectful to him, she will do whatever required to keep Mukhi'from being laughed at in the village.
Love has a long way to go. Respect and understanding is the first stem on that path. Its the small things that binds them over time to each other.