K. Bromberg Hawkin is entirely new and Quinlan is Colton's sister who you see a little bit throughout the series ;-)
Michelle Tuozzo He (Hawk) was introduced when Rylee had Ace and yes Quinlan is Coltens sister so I can't say this is a standalone book because of that.
Debi Carlson-ferrer Quinn is Colton's Sister. Hawk will be her love interest. Looking forward to reading.