This is interesting. To my knowledge the only children Thomas Cain and Christian had were Ann Cain b1842 Jane Cain b1844 and John Cain b1841. If Charles was the son of one the daughters then Ann would have been only abt 12 or Jane only abt 10 at the birth of Charles Kelly. Even John would have been a young 13. Unless Richard Steele, s/o Christain to her first marriage, had a relationship I know nothing of, he would have been aged 26 in 1854. But Richard married Margaret Corlett in 1857 and migrated to Australia - without any children.