Briarwitch Academy 1: A Whisper Before Dawn by KC Kingmaker

“I don’t look for trouble. It finds me: murderous teachers, sexy supernaturals, devious plots.”
Dawn Rose was at peace living as a food-scavenger in her dystopian fringe society. Then she witnessed a brutal murder-by-magic and discovered a couple of cute dumpster babies, and everything went sideways. Now she finds herself at Briarwitch Academy, where she has to survive bullies, classes, and smoldering shifters trying to get in her pants, all while trying to keep a nefarious evil from reaching her people back home…