Hi Cavilover and welcome to the board! I think you will find there are a lot of great people here with a vast amount of knowledge.
To answer your specific question first, I would say Cavaliers are not the easiest to breed, certainly not as easy as many, but they also don't need a c-section every time like some breeds. I'm sure you have read my journal; like I said there, that was probably the two easiest litters we ever had. No problems to speak of unless knee deep in puppy poop counts :lol: Thinking back over the years, I would say probably 1 out of every 3 litters has some kind of problem we have to deal with. We have had several c-sections over the years, got up every 2 hours, 24 hours a day with puppies more times than I care to think about, buried a few that died shortly after birth, and spent many hours with vets with very young puppies.
It sounds like you are going to be doing the testing, that's great and absolutely necessary. Just be sure everything is done by qualified people. For example, your vet cannot do the heart, it has to be done by a cardiologist. I can tell you that most vets can't hear a grade 1 murmer that would disqualify a dog from breeding.
Jane Anderson has a site (
http://www.learntobreed.com/ ) about breeding that is very good. Despite the name, it's actually more about preparing the newcomer to breeding for all the potential problems that can happen, all the work, all the equipment, cost, etc.
Have you spoken to your breeder about this? Unless agreed upon from the beginning, most reputable breeders sell puppies on limited registration which means they cannot be bred or any puppies registered. Your breeder would be the best one to guide you on this. Your breeder would also be the best to help determine if your girl is good enough to be bred. As they say, it takes more than just a pretty face. Your breeder can also help in selecting a good stud dog, which is as important as a good bitch. And, finally, your breeder would be the best person to mentor you as you start out.
Just a couple personal notes: There are two things that I feel strongly about; one is that you should have a mentor that breeds Cavaliers and, two, that if you are breeding, you should also be showing in conformation. I feel you absolutely need a mentor, someone who is just a phone call or short drive away. Yes, some questions can be answered on a board like this, but if a real problem develops, you need someone right there. There's no substitute for a real, live person. And start showing your girl. That's how you begin to understand what makes a dog good for breeding. A dog that may be the perfect pet may not be the best for breeding and showing in the ring will help you know the difference. It may also be the only way to geta reputable breeder to mentor you. I think Kriss and I were showing for close to 2 years before we found someone to mentor us.
I know this got a little long winded and, unfortunately, just scratched the surface. I hope this helps you in your decision. There are other excellent breeders on this site who I hope also chime in with some more insight. Good luck!