At a minimum, you can see below that Mom was friends with Leah and Mereva Rodenberger. More likely the Rodenberger and McClain families were friends. Leah and Mom were the same age. Mereva was four years younger (though she doesn’t look it). When I first saw these photos I thought perhaps the Rodenbergers had a farm and that some of these photos were taken there. But it turns out the Rodenbergers lived in the city of Lebanon, near Second and Oak. Their father Harold was a carpenter for the Southern Pacific Railroad (1920 Census) and a millwright at a paper mill (1930 Census), so not a farmer. Their mother’s name was Merta (apparently a nickname for Myrtle).
Perhaps Mom met Leah at high school or at church. Or the families came into contact somehow—maybe they met because of work Harold might have done on the train station in Tallman or something like that. No matter how the meeting happened, these photos suggest that the girls enjoyed visiting the McClain farm.
Mom’s caption for these first two photos is a little unclear, but what I think she meant was that each girl was photographed with an animal that had been named after her (“namesake” was the word Mom used).

Above is Leah and Leah, apparently.

And if I’m interpreting the caption correctly, above is Mereva and Mereva.
Mom’s caption for the next two photos is “Me with Rodenberger girls.” And indeed the first photo is exactly that.

The girls are standing on the porch of the McClain house. They are (from left): Leah, Mom, Mereva.
This next photo is badly faded, and probably was so even when Mom added the captions to the photo album. As a consequence she may not have been able to see clearly who was in this photo when she wrote the caption—that the three on the horse were not the two Rodenberger girls and her. She was off by just one, though.

Through the magic of digital image processing, you can see what Mom possibly could not. Above we have, from left: Aunt Betty, Mereva, Mom… and a very patient horse. I can only imagine what it must have been like to get three girls in dresses up on that horse for this photo. It’s a fun one, though—worth the trouble!
If this was taken in 1926, Aunt Betty would have been 9, Mereva, 12 and Mom, 16.
This photo hardly counts as a serious equestrian photo. But it is yet another photo of Mom on a horse, interestingly enough.
Here’s a bit of the rest of the story:
Leah Rodenberger married Sidney Grugett (remember him?) in 1930 and they had two sons, Dick and David. Leah’s mother Merta passed away in 1936. The 1940 Census indicates that the Grugetts were living in Lebanon, in a busy household that included not only Sidney, Leah and their sons, but also Leah’s father and her grandfather, her late mother’s father. Sidney worked as a caterpillar operator for a logging firm.
Sidney and also Leah’s father Harold passed away in 1965, within ten days of each other. I don’t know that that was anything more than coincidence.
At some point Leah became a pastor in the Assembly of God denomination and was pastor of a church in Condon, according to her brief obituary in the Lebanon newspaper. She passed away in 1984.
Mereva passed away in 1941 at age 27. I don’t have any details on that.
Very, very interesting!!! The horse picture is cute; thank you, Lloyd, for “rescuing” it.