1. Can you tell me how I can call the stewardess?
2. Can you tell me how I can call the female flight attendant?
[Are both okay? Can we use both? Do you have other names for 'stewardess'?]
3 answers
Both a grammatically correct, but I would go with stewardess. The suffix "ess" tells us that the stewardess is female.
Both are not okay. The word "stewardess" is rather out of fashion. Flight attendants are not just females any more. We would ask how to call the flight attendant without reference to his or her gender. Your grammar is okay in both.
stewardess is just about good