cross breeding

I think you should just enjoy her as a pet, 8 years is too old to breed a dog and cross-breeding is irresponsible anyway. There are no guarantees a JRT x poodle will produce very intelligent dogs. Genetics is very unpredictable, you could very well end up with dogs as stupid as a rock along with the JRTs hyperactivity. Terrible combination IMO.

If you really want to get into breeding though, you should get a purebred show/work-quality puppy from a good breeder who will help you with all questions you might have both with showing and breeding, show the dog to get its championship or get working titles on her or do both, then do all the proper health tests (OFA, CERF) and all other that is required for the breed when she is 2 yrs old, and if she is clear on all that, find a purebred male that will complement your dog's faults.

Breeding is not easy, nor is it cheap. Those tests are expensive, and if you want to breed responsibly you can not skip doing them. You would also be responsible for every puppy bred so you need to be prepared to take back any puppy at any point of its life. IMHO breeding should be left for the professionals who have years upon years of experience in breeding and showing, and those who have not should all spay/neuter their dogs.