Photo credit: Wolverhampton Arts and Heritage
This seems to be a modello by Valerio Castello. You might also wish to send high-res images to Camillo Manzitti and Anna Orlando, as these are the leading experts on Castello.
The Collection have commented: 'We have updated our records to say the artist is possibly Valerio Castello. The picture certainly suits their style. As you say the work is a modello, do you have a suggestion as to the destination or whereabouts of the final work? The painting was donated in 1886 and there is a note on the electronic file which states 'Given as a Tintoretto!', there is no information relating to this note or as to why this was later doubted as no artist is currently recorded.'
If this is by Castello, it can be no later than 1659, when he died, so the current date of "late 17th century" should be changed. As per the NICE Paintings entry, the work was attributed to him in the 18th century and early 19th century. The final version, if extant, may be in private hands in Italy or possibly Peru. Castello is known to have painted this subject more than once.
That woman with her head turned back, viewed from under her chin, is a standard Valerio Castello device, occurring in several Adorations, in Finding of Moses, Moses striking the Rock, Rape of the Sabines, Slaughter of the Innocents etc.