Sherifa never planned to be a science teacher.
"I wanted to study arts or finance, but my father told me teaching was a more secure job. After I spent half my life studying, I didn't want to spend the rest of it teaching," she says.
"I followed my father's advice and, 10 years on, I love science and I love teaching it.
"I can't stop working for another reason. We need my salary of 300 Egyptian pounds ($US 60) a month. It goes straight into the housekeeping."