First of all, it must be clear that the age difference will not change. Then this problem will be easy to handle.

Xiao Fang is 27 years younger than her mother this year, so Xiao Fang is still 27 years younger than her mother after three years. Because my mother's age is four times that of Xiao Fang, it can be changed into: four times that of Xiao Fang-Xiao Fang's age =27. So it can be concluded that Xiao Fang is three times as old as 27.