Passage: In March 1826, when she was 24, she formed a relationship with the 22-year-old William Corder. Marten was an attractive woman and relationships with men from the neighbourhood had already resulted in two children. One died as an infant, the child of William's older brother Thomas, but the other, Thomas Henry, was still alive at the time when Corder met her. Thomas Henry's father, Peter Matthews, did not marry Marten but regularly sent money to provide for the child.William Corder (born 1803) was the son of a local farmer and had a reputation as something of a fraudster and a ladies' man. He was known as "Foxey" at school because of his sly manner. He had fraudulently sold his father's pigs, although his father had settled the matter without involving the law, but Corder had not changed his behaviour. He later obtained money by passing a forged cheque for £93 and he had helped local thief Samuel "Beauty" Smith steal a pig from a neighbouring village. When Smith was questioned by the local constable over the theft, he made a prophetic statement concerning Corder: "I'll be damned if he will not be hung some of these days." Corder had been sent to London in disgrace after his fraudulent sale of the pigs, but he was recalled to Polstead when his brother Thomas drowned attempting to cross a frozen pond. His father and three brothers all died within 18 months of each other and only William remained to run the farm with his mother.

Question: How many children did Marten have?
two