Thanks for sharing the bigger photos Joe
Yep, She is just young. Like everyone else says it can take 2-3 yrs for adult coats to come in. Some are REALLY fluffy at this age, some are not. She will probably end up with a coat more like your Landseer's as an adult. There is a huge range in Newf coats.
My Sophie's coat was very red and very short just a couple weeks ago at the Colorado Newf get together and even in my profile photo. I can't believe how much it has changed in the last couple weeks. So much more fur and thicker, it is also getting so black now. It looks like her dam's coat did at her age.
Also as Nessa mentioned in her post, be sure not to spay too early. Female Newfs should not be spayed until after their first heat .
http://www.naiaonline.org/pdfs/LongTermHealthEffectsOfSpayNeuterInDogs.pdf
You can also look through hundreds of other puppy photos on this forum and see that lots of puppies look very much like your girl at this age. Some have more fur, some have less.
Here is my Lola around your girls age. You can see she had very little fur, but now it is growing in thick, long and gorgeous, although in the new photos it still looks short since she was just spayed so she has none hanging under her, but she still has a way to go since she is only 17 months
Lola as a pup