Thank you Carole.
That is a little odd, for a number of reasons.
William and Eleanor (spelt Ellenor on the ships passenger list) left England on the "John" on the 12th of September 1839. Joseph Hetherington, Nathaniel, John, William, Sarah Jane and Ann Eliza are recorded with them. Sarah Jane died not long after their arrival. They then had another child named Thomas Agen, born in 1841 in South Australia. There are no birth or baptism records before 1842 in South Australia. Followed by 4 more daughters. Rather strangely, there are no Dent births recorded before 1855.
Not only this, but Eleanor had a sister named Hannah. Eleanor's maiden name was Eleanor Beasley, and she had 2 sisters, Hannah and Susannah (this is second hand information, I haven't checked the records yet) and a brother Joseph, who were also baptised at St Michaels. (Parents Joseph Beasley and Susannah). Her brother Joseph married an Anne Lacy and had a child before migrating to South Australia on the "Orleana" on the 29th of February 1840.
A bit of a puzzle it seems, as each of the other children seem to fit. William and Eleanor were married at St. Lawrence's, Foleshill, Oct 10 1831, and lived at Jordan Well before migrating. I would say there were two couples of that name, except that the other children seem to match, and Eleanor is perhaps not such a common name, and a child named Hannah is rather a coincidence.
I don't really know what to make of it.