SOLVED. Middle School Fiction about a girl who meets another and they solve a mystery about Confederate gold

[Kathrynne]

There is a girl, around 12, who lives with her uncle and aunt somewhat in the country, I believe. Her dad doesn't have custody for some reason. Her horses were taken away from her, and her neighbor owns them. She sneaks to the field and starts riding the horses and practicing hiding from cars passing by when she finds her neighbor who has a leg in a cast. They quickly become friends, and somehow they find out about a rumor. Supposedly there is Confederate gold at the bottom of the lake they live by, and they investigate. That's about all I know, except for the fact that the sheriff is heavily involved. I read it around 2015, maybe 2016, and I think it was published 2013, maybe 2014. There's a sequel, but I didn't read the whole thing.

[Kathrynne]

I found out I was way off on some of the storyline, but I was able to figure it out. the girl does live with her uncle, but her dad is in a coma.

The Girl from Felony Bay