Each of the "4" Parlour Suites had one.
On B & C-decks there were "28" so arranged that they could be let to two rooms, or individually to just one of each pair of rooms.
Aft on C-deck and on A-deck there were "14" rooms that each had their own private bathroom, although as with the other rooms on B & C-decks use of intercommunication doorways made it possible in the case of "6" of the C-deck bathrooms to book an additional room.
Yes, the private bathrooms were the same as their public counterparts, save for the size and number of sinks etc. But the walls of the private bathrooms were also bare steel painted white and all of the plumbing was exposed.
No the bathrooms did not feature marble floors, just the same cork linoleum tiles found throughout the ship.