Puja turns 12 on the circled date, which is a Friday. How old will she be on the next birthday that again falls on a Friday?

31 July moves +1 a year, +2 when a 29 February is crossed: 2027 Sat, 2028 Mon, 2029 Tue, 2030 Wed, 2031 Thu, 2032 Sat, 2033 Sun, 2034 Mon, 2035 Tue, 2036 Thu, 2037 Fri. 2037 is 11 years on, so she is 12 + 11 = 23. (18 assumes 6 years always works; 40 adds 28 years.)