Remember Mary Chapin Carpenter? Mary is your hard-knock, single aunt, the one who is all, “You look like you need a mojito and a trip to the shooting range,” which are probably the last two things on earth you really need but whatever works. She’s fiercely political, feminist, whip-smart. She has a generous, pure authenticity, the kind that died somewhere in the 90s. A couple of years ago Mary almost died of a pulmonary embolism,…