Welcome! It's a very exciting time to be adding a new puppy to the family. I do not have experience with them, but I can comment on some things that I have observed from her website.
One of the important ways to be sure that you're getting a pup from healthy parents is to make sure the parents are health tested. Standard poodles in particular can suffer from some inherited diseases and hip dysplasia, so it is important to see these documented results.
I saw no mention of health testing on Gemstone's website, but I did go onto the OFA (orthopedic foundation for animals) website to see if there are records of them completing tests. It seems like over the years, quite a few of their dogs have had health testing done, though only one has fully completed the tests necessary for CHIC certification. All the dogs listed on OFA have either good or fair rated hips. The number of "fair" ratings I see in Gemstone's lines is something that I personally would not be comfortable with. That said, only one of their
current listed breeding dogs shows any records of being health tested (see Gemstone's Show Me The Money). This doesn't necessarily mean the tests haven't been completed for other dogs, but it is most certainly something I would ask about. Hip certification is a standard practice among reputable breeders. You can look on OFA's website to see their list of recommended tests for each breed.
Here is a link
Search results for Gemstone's poodles
Another thing that I would ideally look for in a reputable breeder is demonstration of a dog's structural and temperamental quality. Breeders typically do this by titling a dog in conformation, obedience, or other performance events. I think I've seen all the pedigrees of Gemstone's dogs and some of them come from conformation lines, but aren't titled themselves. In addition, many of the dogs look to be of lines where none of the family tree has any titles. Some of them look like they have decent structure, and others look like their structure could be lacking. There are plenty of excellent dogs that don't have titles, but it's nice to see those in a pedigree as evidence of quality dogs.
Other things-
I really dislike that they have a paypal button to put a deposit on puppies. This makes it appear that there is no application, no interview, and nothing to make sure the pups are going to good homes. Maybe this does still happen somehow, but I do not like how easy they make it to put a deposit. My dog's breeder talked to me for many hours before she agreed to allow me to put a deposit. And all reputable breeders that I know require application and approval.
No mention of a puppy contract here, so that is something I'd ask about. Puppy contracts can be very important to consider. Such as what kind of health guarantee do they offer (like if puppy comes down with Parvo 12 hours after you pick it up) and what sort of guarantee do they have against inherited genetic diseases. Also you want to know what rules they have on when you are required to spay/neuter.
This is a breeder that breeds dogs as a full time business to make money. That doesn't make them bad. I would say I personally prefer preservation hobby breeders because their purpose in breeding is to breed better dogs because they love the breed. Many will say that breeding done right is near impossible to profit from. So when I see a breeder that is operating as a business, it raises questions about what corners they're cutting. The best reputable hobby breeders aren't always easy to contact because they have busy lives and only breed their dogs because they are passionate about them.
The question of purchasing from a given breeder is very personal, and I only mention these things to help you make an educated decision.