Four years ago, it should be that the whole family was four years younger, and the total * * * was 4*4= 16 years younger.

7 1- 16=55, which is smaller than 56 1, indicating that the younger son was not born four years ago, but the son was born three years ago.

So now my son is 3 years old and my daughter is 5 years old.

Then the sum of parents' ages is: 7 1-5-3=63.

Father is three years older than mother, so the age of father is (63+3)/2=33.

Mother's age is 30.