Child’s scarf tutorial

The Golden Hands Knitting and Crochet Encyclopedia Alternating Cables pattern swatch is as follows.

1st Row. P1, *K4, P1, rep from * to end.

2nd Row. K1, *P4, K1, rep from * to end.

3rd Row. P1, * K4, P1, C4F, P1, rep from * to end.

4th Row. K1, *P4, K1, rep from * to end.

5th Row. P1, *K4, P1, rep from * to end.

6th Row. K1, *P4, K1, rep from * to end.

7th Row. P1, *C4F, P1, K4, P1, rep from * to end.

8th Row. K1, *P4, K1, rep from * to end.

Repeat 8 rows of pattern until desired length.

Now at 52cm in length, how long do you suppose a child’s scarf should be?