Newfies don't require a lot of space, since they're pretty mellow dogs. Space for the doggie basics mentioned above would be adequate. Walking up and down lots of apartment steps would not be advisable for puppies, while their joints and bones are still growing. And you'd have to think about how you plan on taking her outside for potty breaks (particularly when it's still a puppy when you have to take them outside more often). I think Rosie would have done perfectly fine if she lived with us in our old apartment. We had more than enough space to accommodate a sleepy, lazy Newf.
I would also check with the apartment manager to see if they have size restrictions. Most apartment places do.
