See i thought you said you had two newfs besides!
LOL
anyway, i hope i made the point, that the training is a must and the breeder hopefully will point out the good and bad, the grooming the care the everything.
if not, i would run and run fast.
as far as them being active, i tell you, the lines i deal with keep you on your toes, and i am happy for that, becouse i see so much potential in the drive necessary to do the job, the thinking processes they have, and people can support what i say, and, the challenge is met with proper time spent with the pup, proper techniques used in training them.
A vet is good for medical advice but, they normally like to see newfs 10 pounds over what they should be, they also do not know dietary needs, they are medical.
your breeder should coach you on the proper diet and stay in close contact with the growth the pup experiences, many pups will grow differently and require different nutricion at certain points in their growth.
Kudos to the pyr for being a good girl now
and kudos to you for being so dedicated!