How old is too old for breeding?

I have a 100% het Albino female from 2003 that had successfully bred in 2006 and 2007 with an albino. She's the only snake I have left after all this time.

Has she passed her prime for breeding?

My understanding is that snakes do not have a "prime" for breeding - once sexually mature, they can produce offspring for the duration of their lives. In the wild, an animal which is unable to pass on genes is beyond its natural usefulness. Some breeders may "retire" a snake, but not out of necessity - if the animal produces healthy offspring, there is no reason they cannot continue to breed for many years. :)