We conversed on January 1 and her birthday was on December 31. So, the day before yesterday on Dec. 30th she was 22 and he turned 23 on Dec. 31. So her next birthday, when she turns 24, would be Dec. 31 of the same year the question was asked. However, next years birthday would be the following year on Dec. 31, when she would be 25.
Solution #1 - Squares
First, Carl divides his as to reserve to himself one-fourth in the form of a square.
Then, Carl takes the remaining 3/4 shape and scales it down by 1/4. He then, multiplies the shape into 4 identically shaped pieces, and aranges them so that they fit into the original 3/4 shape.
Solution #2 - Rectangles
First, create a triangle that is 1/4 the size of the square.
Now, with straight lines, create two squares.
Proceed to disect the two squares with horizontal lines creating 4 triangles.
Then, disect one of the resultuing triangles from each square. The shape of land for each of his four children is divided evenly and is the same shape.