This was a nostalgic re-read for me. I read this book originally as a teenager when it was republished in a 3-1 omnibus edition. I wasn't particularly into horses just going through a stage of reading everything.

This is a teenage siblings solving a mystery with horses book. There is some violence and cruelty to horses but it is not graphically described. It's basically what existed before the term cozy mystery was used heavily. 

If you enjoyed Nancy Drew and The Hardy Boys you will probably like Linda Craig. 

If you are looking for complicated plot lines, diverse characters or a surprise ending you might want to skip this one.