I would suggest you artificial inseminate her. Your vet should be able to do it right there in the clinic with no problems. Another thing the vet can do is vaginal cytology to determine when will be the best time to breed her. He/she will swab the lining of the vagina and then rub the swab on a glass slide and stain it. A quick look under the microscope will tell them how close she is, or if she is ready. If the male is cooperative, he should be easy to collect.