Yes, both sentences are correct, but in different contexts.
Sentence a. is correct if Fatima still has an opportunity to see snow during her lifetime.
For example, Fatima lives in a Mediterranean country where she has no opportunity to see snow. Now she is planning to go to Canada to live, and she's wondering how the snow will be.
Sentence b. is correct if Fatima will not have any opportunity to see snow. She may be very old, or never planning to travel, or even dead. The past tense, not the present perfect, is used to talk about people who are no longer alive.