What do Aisha and Nadira learn from their mother in Section 7: Chapter 9? Who approaches, attempting to help?

Visiting Ali-uncle, Nadira and Aisha explain what is going on, and he tells them Abba saved $3000 for their college tuition secretly in case they could not become legal because he did not want his daughters to be disappointed. He agrees to write a letter, explaining why Abba gave money to the mosque.