I would say that this confirms the parents as John FELL and Isabella STEVENSON, especially as Jane used "Stevenson" as a middle name for one of her children and "Nelson" (name of a sibling) for another.

According to IGI, John FAYLE and Isabella STEVENSON married 12 Nov 1791 Braddan. IGI gives 6 children under FELL and 2 children under FAYLE, from 1792 to 1817. In addition, there's one with parents Paul Fell and Bella Stevenson and another where the mother is Elizabeth Stevenson and yet another with parents Robert Fell and Isabella Stephen. Most kids are St George Douglas, but Braddan is in there too. There is no Jane and not much room to fit one in around 1809, but there are some gaps earlier and later.

I wonder if one of the children, such as "Cathe" 7 Jan 1810 is actually "Jane". You should review the original register to see if there's a transcription mistake.

You were lucky that Jane married a second time, and so you could get her father.

There's a burial for a Paul FELL 23 Dec 1836 age 79 at Braddan. No Will on the index though. Isabella is less certain, but since she doesn't seem to be on the 1841 or 1851, I'd favour the burial of Isabella FAYLE 4 Sep 1832 age 59 at Braddan. No will for her either.

If this is the right person and the age is correct, Isabella would be born ca 1773. There is an Isabel Stevenson bp 16 Jan 1774 at Braddan, d of John STEVENSON and Jane CANNEL.

Nothing obvious for Paul, born ca 1757. The nearest on the IGI is Paul FAYLE, s of James FAYLE and Mary CRY 7 Feb 1762 at Lezayre but he doesn't seem like a good fit. I checked FAYLE and FELL and SAYLE (F and S often confused when transcribing).

Hopefully there's enough here for you to carry on with.