I've been reading Oliver Twist recently and would like some background and context on how it was for the workhouse children, and children of poverty such as orphans, at the time. All suggestions greatly appreciated.
Try the works of Jane Humphries. Humphries is Professor of Economic History (Oxford) but has also published on gender history and the links between family and economics. With respect to your question I especially recommend "Childhood and Child Labour in the British Industrial Revolution" published in 2010. For a shorter version see Humphries' article "Care and Cruelty in the Workhouse". You will find additional relevant texts in the same volume.
Bibliographical notes: