IMO, to begin with, someone who mixes two purebreeds isn't a good breeder to begin with. Now that's said. Research the two different breeds independently. All breeds have their abnormalties. Has she testes for those(like in Cavaliers, it's heart and patella problems.) Depending on the personality of the person you're buying the dog for, looks for the most outgoing if you want a dog that's kind of a handfull and, well, outgoing. I would go against the shy one, they might grow up scared their whole life and sometimes the scared turns into antisocial and fear biting, my personal preference is somewhere in between, hoping the dog grows to be somewhat independent but listens well, you know? See if the breeder named them, their names usually go with their distinct personalities. Ask the breeder which one she suggests. Ask her when the last time they were wormed and if they've had their first shots. Look up when this perticular breed is ready age wise to go home and make sure she doesn't try and sell them to you early. Ask if this is her first litter and if she has had any puppies returned to her before for any reason. Make sure you take the puppy in as soon as possible to be checked by a vet, and make sure you tell her you're going to be doing that and you will let her know if any problems come up that she needs to be responsible for. That's all I can think of right now... good luck dog hunting. If my favorite breed, the Cavalier King Charles, weren't so expensive, I'd tell you to look into them. They are well rounded and total sweet hearts, not to mention the cutest things ever. I highly suggest not getting a mixed breed from a breeder, you never know what you'll end up with.