Hi Sashka,
First Class bathroom facilities varied per deck they were located on. A-Deck featured communal restrooms and several private, public bathrooms.
The only A-Deck cabins to feature their own private bathrooms were A-36 and A-37.
First Class on B Deck was different. The period or special suites had their own private bath and rest rooms, while the cabins further fore and aft of these cabins made use of similar, communal restrooms and private bathrooms, the same is true of C Deck cabins.
D and E-Deck cabins would all have to share the communal facilities.
Best Regards,
Brian
[Moderator's note: This post, originally posted in a separate thread outside of this subtopic, has been moved to the one addressing the same subject. JDT]