I think her fingers are on either side of an exposed hammer, not through a lever loop (note the buttplate, that’s the “top” of the rifle facing the camera). I think they’re single-shots of some kind - possibly Remington Rolling Block designs as previously speculated. Could be Marlin-Ballards, too.
Without side view it’s difficult
to discern. You could well be correct.
There is is another model to
consider. A Stevens Ladies 56 25-20.
Purely a guess on my part, but I
don’t believe a single shot would
be considered for shooting
completions.