To provide a complete answer, be sure to mention both the physical reason (pock-marks) and the mental reason (being a slow learner) that contributed to her father's anxiety about her marriage prospects.
Bholi's father was worried about her because she lacked both good looks and intelligence. An attack of smallpox had left her with pock-marks all over her face. Furthermore, a head injury in her childhood had made her a slow learner. Her father despaired that with these disadvantages, it would be extremely difficult to find a suitable husband for her.