Sentence:  This included Mamma , jolly , generous , and pretty , with whom they all fell in love , just as Papa had first fallen in love with her Mamma before he chose her ; and when a young man like Morris Jastrow had enjoyed the Szold hospitality , he felt <WSD>obliged</WSD> to send his respects and his gifts not merely to Henrietta , in whom he was really interested , but to all the Szold girls and Mamma . 
Meaning of the word marked with <WSD> tags:  under a moral obligation to do something