WendyB I would suggest reading the Jack Daniels series in order if at all possible. Each book builds a bit on the previous one, and you'll understand the characters and their interactions better if you do.
Tammy I didn't read book 2 or 3 before reading this one. However, I had read the first book so I was familiar with the main character. I didn't notice any issues where I felt like I didn't understand something because I had missed it in another book. That said I did get a 4 pack bundle of Hannah Swenson mysteries. They were in digital format and they were out of order. It went something weird like book 13, book 3, book 8... So I did feel like I was jerked around in time because she was married somewhere in there and then she wasn't. Joanna Fluke writes that series.