You know it is impolite to ask a lady her age.
But I can offer you some interesting answers.
(I do believe you are a gentleman, so just for fun and for helping new immigrant learning English.)

Q: If you don't mind, can you tell me how old you are?

A1. I am always 29.99
A2. I am older some than some, but younger than others
A3. I have not yet been as old as centuries
A4. I am twenty this year, but eighteen next year....