Most airlines have a line in their T&Cs that reads something like this one from Air Canada: "

• Your carry-on baggage must be light enough that you can store it in the overhead bin unassisted."

People of any gender who expect others to handle this job for them are not worthy of any help or sympathy whatsoever in my opinion. You brought it on board, you deal with it. If someone wants to give a more polite response than just a simple 'no', I can understand that. I suggest this: 'Sorry, not in my job description', delivered with a smile. That will leave the person confused as to what you meant but clear on the fact that you aren't going to do it.