confusing math riddle need help fast

John is talking to Mary while working on a deal book at 2AM. Mary learns that John’s sister has three children. “How old are the children?” asks Mark. “Well,” replies John, “the product of their ages is 36.” “Hmmm, the sum of their ages is the same as this figure right here,” says John pointing at the spreadsheet. “Still not enough information,” says Mary after thinking for a minute. “The eldest is dyslexic,” says John. How old are the children?