
Hiya,
It certainly sounds as if you are doing all the right things! Well done you :)
When you meet the breeder and her dogs on Saturday you'll probably know straight away if you have "a good feeling" about her set-up - how the dogs are kept, how they interact with her/you/each other. Be prepared to be thoroughly "grilled" about why you want a newfoundland and about your personal circumstances - a good breeder wants "her babies" to go to lifelong, loving homes.
Tell her if you are even vaguely interested in showing - then she'll know you don't want a pup with minor defects (mismarks, slightly wrong mouth etc) which won't affect the pup at all but would bar it from the showring.
Let us know how you get on. :)