Lottie’s still 19 for another seven or so months. Claire’s 19 or 20; we’ve never learned when her birthday is. Shauna turned 20 last month, and Mildred the month before. Sonny’s 19; his birthday’s not for another month (Christmas Day! because of course it is). Jack is possibly 50 now? Otherwise in the same category as Claire and Linton, who’s also 19–20 depending on an unknown birthday.