Good but missing something

I enjoy M.K Eidem's other series. I enjoyed this storyline but kept feeling like something was missing. A big something. While the heroine, Callie was mysterious for valid reasons I realized it felt like I was reading a 2nd or 3rd book in a series. By the end I felt even more so. It felt like her parents had a full story worth telling and to give a fuller background and depth to Callie's storyline. Maybe its because I'm used to Eidem doing series that I feel let down that this felt incomplete. In addition to feeling there should have been at least 1 book before this it ended feeling like there could be more to tell after this. While her brother's were often mentioned there was not even 1 interaction with any of them throughout this book. So while there was not any kind of cliffhanger it just feels like there could be so much potential for a series to expand on this world and characters.