Hello Roger,
Are you certain that both your relatives were born in Douglas ?

A Hugh Quilliam married an Elizabeth Kelly in Ballaugh 20 Nov. 1830. Hugh was one of twelve children listed on IGI as born to John Quilliam and Esther Corris in Patrick and christened 17 Feb 1805. Elizabeth may have been the daughter of Isabel Kelly ( no father mentioned ) and christened 14 Jan 1810 in Ballaugh.

The name Hugh is sometimes transposed to Ewan or Evan so on 3rd June 1831 Evan and Elizabeth Quilliam arrived at New York on the Packet Ship Isaac Hicks from Liverpool. Their belongings are listed as 2 chests of clothing, a bed and bedding , and cooking utensils.

By 1850 they are listed in the 1st Ward Cleveland :-

Hugh Quilliam 44 IOM.
Elizabeth .. 39 IOM
John 18 New York
Esther Jane 16 Ohio
Christiana 14 Ohio
William 13 Ohio
Mary 9 Ohio
Elizabeth 4 Ohio
Sephronia 1 Ohio

Nearby is another Esther J. 19 IOM but I don't know if she is connected.

Hope you recognise some of this,

Len Faragher