Take a rag and rub it all over the buck...the nasty dripping parts are best, also top of head. Take the rag to the doe and keep it in front of her. Better is to bring the buck around her and see if it triggers her heat. If she is seasonal then you may be too late, you could try. Our Lamancha was bred last year on Jan31st Kidded June 24th.
Even when they bred our girls, there was the appearance of... well, rape. they never seemed interested, always on the run. And when the boys finished, the girls squatted and got rid of the result. It worked! Which is good, but I thought my gosh, she wasn't ready after 3 days of bucky stupidity.
If you don't have a buck on your property, a buck may work.... I'm not sure how great it is to bring your doe into heat, but it really helps to tell once she is.
You will need a rag, a jar with a tight lid, and a buck in rut. Take the rag and rub all over the bucks face/head and belly. Put the rag into the jar and cover tightly. When you get home open the jar under your doe's nose several times a day. When the doe gets excited or tries to get into the jar, its time to visit the buck.