What is a female or gender neutral form of gentleman that relays the same tone of respect? [duplicate]

Solution 1:

Unfortunately, 'lady' has a paternalistic connotation, and it is best to refer to both sexes as clients, customers, vendors, manager, assistant... -when possible. IOW, avoid referring to their sex but only their position.

Solution 2:

Gentlemen and ladies lend me your ears! You seem to be looking for lady.

Solution 3:

A gender-neutral, respectful word to describe a customer is "customer". Even in communications that are likely to be shared with said customer, in practice I've found that the word is far less likely to offend. This is especially true in those cases where your customer sounds like a "gentleman" on the phone, but is in fact a "lady" (or vice versa).

Your example phrase would therefore sound just as professional and respectful if spoken thusly:

"I spoke with the customer about the issue he was having and it turned out he forgot to turn his computer on."

Of course, using "he" in the same sentence negates the gender neutrality of the term you use no matter how carefully you choose it, but that's far too broad to properly cover in detail here.