Let the age of Jen 2 years later be x,
age of jack two years later = 2x
total age of jack and jen now = 2x + x - 2 - 2
= 3x - 4
3x - 4 = 66
3x = 70
x = 70/3
= 23.3 (to three significant figures)
age of jen now = x - 2
= 23.3 - 2
= 21.3
Jen is 21.3 years old now.