Answer:
I think the best answer would be he died of an unknown illness because Mr. Summers is referring to a man that is Watson. Normally people refer "head" of the family as the man. And since his mother is assumed she's alone, she has a man to do the work. I don't think I explained this properly but I hope it helps! :)
Fifty five is Carole's current age
The most appropriate synonym for the word children would be "Youngster"
Hope this helps!
