Thanks for those extra baptisms, keyboard, that's useful.
As for Jane Heale' birth place, yes, in the 1881 census it's given as Dilling, Devon, but in the 1891 census it's given as Torquay. Perhaps she was trying to find somewhere that people might have heard of in London (where she ended up), or perhaps the person filling in the form wasn't too sure exactly where she'd been born.
I agree about the Elizabeth Jane who was born in Dolton in the 1861 census with Mary Heale was probably a granddaughter rather than a daughter. There is a record for that baptism on FindMyPast, which might give her parents.
So the Caleb Heale who died in 1839 was born in 1876, or thereabouts. I wondered whether he might have been a brother of John Heale, and so our Caleb's uncle, but I have no way of knowing. None of the family trees on Ancestry mention that, but then they don't give their sources, so who knows where they got their information from.
This marriage between Caleb Heale and Grace Heale is also a puzzler. They must have been cousins of a sort, first or second or what have you. My brain is starting to hurt with all these relations now!
Thanks for looking all that up. Things are graudally becoming clearer (in general!).