I've been following this discussion and not yet ready to make any conclusions on who's right and who's wrong re the Looneys. However, I do know a bit about the Stowell children mentioned in the 1835 will (grandchildren of the testator John Looney, and children of his daughter Margaret).

As Sue noted, William Stowell married Margaret Looney 8 Jun 1828, and had the two children Isabella and Margaret that are mentioned in the 1835 will. What hasn't been mentioned yet is that the widow Margaret Stowell then married a widower named Edward Gelling 8 Aug 1835 Maughold, and they had a child named Margaret bapt 3 Jul 1836 Maughold. Edward Gelling will be the [brand new] husband of the daughter Margaret that John Looney carefully ensures his estate is not to be used to pay off his debts.

As a Gelling researcher, I've had great difficulty figuring out who this Edward Gelling is or what happened to him, but that's not relevant for the Looney discussion. However, what might be relevant is the last child of Margaret was born 1836. If Margaret was the d/o John Looney/Isab Camaish b 1796, she'd be 40. If Margaret was the d/o John Looney/Mgt Hutchin b 1785, she'd be 51. Without knowing any other background, I'd have to pick the 1796 Margaret as the right one.

This is what I have for census entries for Margaret Gelling, prev Stowell, als Looney. It shows that life was difficult for her in her later years. Ages are quite a bit out on some of them.

1841 census: can't find them.

1851 census at Lezayre St, Ramsey HO107/2524 310 pg 5 #17
Margaret GELLING, Head W 57 Pauper, b Isle of Man Maughold
William SOWELL, Son U 20 Labourer, b Isle of Man Maughold [from prev marr]

1861 census at Curpheys Lane, Ramsey RG9/4429 16 pg 25 #106 (543281)
Margaret GELLING, Head Widow 60, b Isle of Man Maughold
William STOLE, Son Un 28 Laborer, b Isle of Man Maughold
Margaret GELLING, Daur Un 26, b Isle of Man Maughold
William RADCLIFFE, Grandson Un 5, b Isle of Man Ramsey [illeg son of Margt?]
Harry THOMPSON, Son? Unm 2, b Isle of Man Ramsey [who is he?]

I don't have anything for Margaret Gelling (Stowell/Looney) after the 1861 census.

Daughter Margaret Gelling is in the same household as Rachel Looney in the 1841 census. As we know, Rachel's husband John had gone to South Australia, and Rachel and son John Joseph joined him in 1842.
Margaret Gelling seemed to have several children by different fathers, without marrying any of them.

1841 census at High Bawnian? Cottage, Maughold HO107/1464/7 3 33 pg 1 (464356)
Rachail LOONEY 54 Inn Keeper Y [Rachel Redhead, widow of John]
John J LOONEY 21 Y
Margt LOONEY 23 Y
Sarah LOONEY 26? Y [last digit smeared]
>Margt GELLING 4 Y [related to above Looney family through her mother?]
Henry McKEWIN 25 MS I
Barney BESENNY 20 F.S. I [age in male column but occup written "F S"]
Wm JONSTON 20 Army S
Sarah LOONEY 25 Y

1851 census at King Street, Ramsey HO107/2524 363 pg 25 #119
Marg't GELLING, Servt U 14 House Servant, b Isle of Man Maughold
at home of Robert Crowe 32 Publican and family

1861 she is with her mother (above)

1871 census at 3 Curphey's Lane, Ramsey RG1-/5773 133 pg 24 #116 (895842)
John CANNON, Head Widr 44 Tailor, b Isle of Man Ballaugh
Margaret GELLING, Serv Unm 35 Housekeeper, b Isle of Man Maughold
George CANNON, Son 12 Scholar, b Isle of Man Ramsey
Jane CANNON, Daur 2, b Isle of Man Ramsey
William SHOLL, Lodger Unm 40 Labourer, b Isle of Man Ramsey [Margaret's half-brother William Stowell?]

1881 census at 7 Quayles Court, Maughold RG11/5601 3 pg 6 #143
John CANNON, Head Mar 50, b Isle of Man [occupation blank]
Margt CANNON, Wife Mar 44, b Isle of Man
Jane CANNON, Daur Unm 11, b Isle of Man
Isabel CANNON, Daur Unm 9, b Isle of Man
Charles CANNON, Son Unm 4, b Isle of Man
William STOWELL, Boarder Unm 45, b Isle of Man

This may be her: Burial: GELLING, Margaret 56 Mau 18 Jul 1890 (BL Web)

1891 census: can't find any of them

The son William Stowell, b 1830,shows up in several of the census's above, other than I can't find him in 1841 (he'd be 10).
The daughter Isabella, b 1828 could be the 12yo F.S. at the home of William Thorburne, builder age 30 b Scotland, at Victoria Place, Concan. After that, I have no idea.