How many children did David Mama have?

From the text:

The whole family were exactly like Zambo : large, tough, and ungainly, to judge from these pictures. Ungainly they were without a doubt - father, mother, and all three children. (The two younger boys were absent during my visit to Kala ; from what I heard they sounded near delinquents.)

I like Jill W's answer. Why does this site not provide interactive features like liking and nested response?