I know what it is about the rescue-Angel that interests me. Several points. Ponder these.
1. The contrast between reality and these paintings. They appeared at or shortly after a time when little kids were working and dying in the mines. Or in chimneys. Or on the street. Where were the rescue-Angels? They were waiting in dangerous places. Often at rivers and gorges. That's where they were!

2. Are they really rescue-Angels at all? Are they just waiting to carry away the souls of accident victims?

3. Are they the last remnants of Water-Spirits, actually ready to lure mortals into the water. Like it was for Hylas and Narcissis and later Henry Lee and George Collins?

4. Or maybe they are unable to reverse a death and can only modify it by giving eternal life to souls? Rather like the Good-Faerie at Sleeping Beauty's birthday party.

5. Are even the pretty Angels hovering around childrens' beds there just in case a child should die in the night. Are they Faeries waiting for a chance to do a quick switch-a-roo with a Faerie-changling?

6. Angels on battlefields can't (won't?) stop wars.

That's enough! And you thought it was sweetness and peace that I was into. Cheers and stay away from Angels until we know more about them, I say. Joy