All Saints was definitely run as an orphanage in the 1920's. My mother and aunts were all there. One of them is still alive. She says that the nuns were strict but kind. The children all went to local schools and left to go to work places wherever they could be found. My mother went to a large house as a trainee nanny. Some went to relatives, who took them in whilst they found work.
The 3 children were not actually orphans, but the family was very poor.
You probably are aware of all of this by now, as the post is old, but I have only just joined and seen it.