After being comforted by her mother, Mina lied and said that she had been making a new budget in her mind and it was distracting her. That was close to the truth, she was thinking about the money she had sent her parents and she wondered if it made more sense for her to pay her uncle directly, but knowing the man, he would charge her parents as well.
Mina knew her father would not want to offend his adoptive brother, so he would pay whatever he was being asked to pay, regardless of what Mina said. She needed to find a way to pay her uncle while simultaneously having her parents aware of her actions and she needed a way to offer them the choice without insulting them. If she brought it up now, it would look as though she were telling her father she did not trust him, but that was not the case. She just wanted to make sure that he took care of himself.