Medium-stroppy Arizona teenager Tiger Tolliver is chafing against her single mom’s pernickety restrictions. After one final falling-out over a dress, life changes forever for Tiger when June Tolliver dies of an embolism and the narrative takes a darker turn. Tiger has never known her father and suddenly finds herself a ward of the state, entering the foster system and meeting other waifs on the margins of society. Scenes such as the viewing of the body are sensitively handled, but 400-plus pages of “My Mom Died Now What” (which Tiger wishes she had printed on a T-shirt) is heavy going. Thankfully, Tiger is a spunky, original creation, and Glasgow gives glimpses of well-meaning and often effective interventions from the adult world. Mourning — aka “the Big Suck” — is relentless; but then, that’s the point.