+-----+-----+-----+-----+-----+
| WAS | NOW | WAS | OLD | WAS |
+-----+-----+-----+-----+-----+
| AS  | AMY | ANN | HALF| AS  |
+-----+-----+-----+-----+-----+
| IS  |  A  | OLD |  IS |WHEN |    
+-----+-----+-----+-----+-----+
| AS  | AMY | ANN |THIRD| AS  |
+-----+-----+-----+-----+-----+

You can make a 20 word sentence about the ages of Amy and Ann by following the jumps of a chess knight from word to word in the above diagram.

Given that Amy is in her teens, and each of the ages of Amy and Ann is expressible in integer number of years, how old is each of Amy and Ann?

Note: No cell can be visited more than once.