The baby's room floor looks like hardwood that's been painted with a white wash of color. I cut the boards out of 1/16" balsa and then glued them down to poster board before installing the floor. I'm learning the easiest way to do the inside of a dollhouse is to make the floors and walls on top of a cardboard pattern first and then just glue the whole thing in. That way, you get an exact fit and it's easy to reach all the corners. Any little spaces you fill in with spackling and smooth out. It really is the best way to do it.
The little nail holes were made with the end of a piece of florist's wire pushed into the soft wood. The railing was made the same way the downstairs rail was made - only not as fiddly.
The floor was finished with a coat of matte Mod Podge and then polished with wax. The little cracks give it character. I just love the clean look of the light washed wood. Love it! It's so right for a baby's room.