The stewardesses were quite few in number and nearly all assigned to First Class. They could be summoned by a system of electric bells. The short answer to what was expected of them was anything within reason, ranging from the usual housekeeping and room service duties of hotel staff to the more personal tasks involved in looking after 'their' passengers, which might include providing advice or just a sympathetic ear. Many of the ladies in First Class, however, had their own maids on board and no doubt kept them busy too. If you want to know more about the life and work of a stewardess, the ideal source is the book: Titanic Survivor - the memoirs of Violet Jessop Stewardess.