How do i find out how old my aunt is?

its her birthday tomorrow and my entire family is really curious. we dont know what to put on the card or how many candles to light. her house was flooded and the birth certificate was destroyed. she was born in hungary, and we cant get information from the embassy because its a long process with lots of paper work, and we’re just plain lazy. we went to the doctor with her, and on her file, it doesnt say.

we know that she’s either 98, 99 or 100. whenever we ask, she pretends not to hear and talks about a recent film or a book she read.