The Mage of Motor Avenue. The Mage of Motor Avenue Series, #1

Lois Peterson has a strong instinct for self-preservation, which she attributes to her age (seventy-three), her location (Los Angeles), and her ex-husband's hobby (summoning demons). So when the girl who swears she's not a werewolf begs for help, Lois is torn. Self-preservation has led her to reject the use of her own magical powers and to embrace the motto of her adopted hometown: it's safer not to give a damn.
But Lois is a decent human being and also the girl is very polite. Before Lois can act, the girl is kidnapped. The girl's friend, an emotional squid with the disconcerting ability to shift into human, seems to think Lois ought to do something to stop the wizard who's creating animal-weres against their will. Reluctantly, Lois agrees to help. Armed with a cane that doubles as a stun gun and expressing a strong  aversion to being called a wizard, she sets out to stop the evil-doer.
But it's going to take more than a well-developed instinct for self-preservation to save her skin. It's going to take ingenuity, resourcefulness, and a grizzly bear. Along the way, Lois has to confront her demons (including the figurative ones), her ex-husband's obsession with their past, and her own unwillingness to accept who she is. In the process, she learns you're never too old to come of age.