If you are concerned about whether a hernia is a risk for breeding a dog, then you definitely are too early in the learning process -- about dogs, breeding and cavaliers in particular -- to be considering breeding cavaliers. Breeding is infinitely more complex than this especially in this breed with its very high rates of affectedness with mitral valve disease and syringomyelia.
But there are other problems with the fact that you have made this post.
One of the main rules on this site is 'no breeding advice' for reasons that are very clearly stated in the Getting Started section. However, as you know, I also sent you quite a long private post regarding your FIRST puppy. I explained that the reason you'd been unable to obtain a show/breeding dog from any of the good breeders you approached, and why you sadly ended up dealing with a trash breeder and a convicted felon, is that NO reputable breeder would ever sell anyone a puppy for showing and breeding, unless the person has proven their capabilities and serious intention to put health foremost, knows the breed, understands the genetics of breeding and this breed in particular (as both the key health issues are polygenetic and inheritence is complex), and can breed only to BETTER the breed, not place more pressure on it.
As others have said, there is a lot of good advice on how to get PROPERLY involved with the breed and also, in the Library section, the serious things you should consider before breeding in a general sense. If you care about the breed, much less about the families that might take your puppies, you will take the time to do so, get a proper breeder mentor who also shows, and can help pass on so much valuable direct advice to you.
I am really disheartened though that none of what I said before registered, and that to the contrary, you have even posted again noting your intention to breed. The reason I took the time to respond privately was to offer some support in a discouraging situation for you and suggest some possible legal recourse, as well as to talk a bit about why responsible breeding is so very necessary.
I sincerely hope you someday do come to love and cherish this breed as so many of us do here -- because when you TRULY do, you will be horrified you ever even considered breeding in this casual way and won't be approaching breeding in the way that you are now.
At this time I don't feel you are ready to make contributions to this community so am suspending your account.