Hi,
You count day one as the first day of bleeding. Then on the 11 - 14 day she should be ready as her bleeding would of either stopped or sometimes if cold be just light. If she is letting him lick her and throwing her tail over she is ready. She still could mate as some bitchs up until the 20th day. It all depends on the dog. Your know when she has finished as when you rub near the spot she will get frisky and throw her tail over. If she doesn't then she has finished.
I know I am going to have trouble I think with my bitch Marley when I come to mate her. Other dogs have had