Hi Pat,
Regarding Mary Jane Loates. As she was about 4 when orphaned I would assume she went to the nearest Poor Law Union ('workhouse'). They apparently didn't bother chasing up possible relatves in those days. (I have a similar thing in my family - an 11 year-old orphan was packed off to Canada despite having siblings, uncles, aunts, grandparents et al).
In a workhouse she would have been given various tasks from an early age and by the time she was a teenager she would have made an ideal housekeeper, lady's maid, etc. If she was hired by a good family she may have travelled overseas with them, especially if the master was a firebrand Anglican parson intent on converting the pagan world !!!
If she was a resourceful girl sha may have gone overseas by herself. (Again in my family I have an Eliza Loates who was last heard of as a 15 year-old teacher in 1851. She finally turned up in the US 1880 census).
Did she drop the 'Mary' and use 'Jane' as her given name?
Was it changed 'accidently'? (Getting back to my lot, when a birth was registered in Kent either the registrar was hard of hearing or the informant's speech was adrift because Loates became Loakes, a name which he and his children retained.
Also, in Cambridgeshire there is a case of mis- translation. A family called Toates has been recorded as Loates. Checking the original , a Victorian longhand ' T' hs been transcribed as an 'L'.
These are just a few alternatives you can try
Be lucky
Andy Loates