During the 19th C Agriculture (as in the area around Mkt Harborough) underwent a severe depression.
This resulted in the younger & single members of families (those without family responsibilities) to seek work in other areas.
Such as these towns on the Cumbrian Coast:~
Barrow in Furness,
http://en.wikipedia.org/wiki/Barrow-in-Furness
Whitehaven.
http://en.wikipedia.org/wiki/Whitehaven
Maryport
http://en.wikipedia.org/wiki/Maryport
If you read these pages from Wikipedia it won't take you long to realise that this short part of the Cumbrian Coast was(in the mid 19th C) probably the largest coastal industrial area in Britain,and as such was probably crying out for workers;being as the area that it was in was sparsely populated.
You also have to consider that this coast would also have had a large fishing fleet.
I have no doubt that a brother and sister (going somewhere new and strange) would have felt happier and more secure together than going alone.
Sadly,people had to travel what was(to them) large distances to obtain work.
Of course some families went as far as America and Australia to do the same,so moving to Cumbria was probably an easier option.