I am sorry to hear about your prognosis. As someone with a Geek child (now 20) I can offer some stuff for you. There are two ways to go about this: Regular Advice or Geek advice. You can go exclusively geek advice, but that is a short list and technically rather short sighted. You can give regular advice, but can add geek references would probably be more appropriate.
* How to pick a good mate (interests, money, sex, religion, etc.) Maybe include stories of your wife/your courting
* How to succeed a marriage (how to fight, alone time, sex, money, etc.)
* How to be a good partner in a relationship (no passive/aggressive, fight fair, etc.)
* Sex in general
* Self Esteem (how she is good how she is, don't change, positive notes, etc.)
* Geeky stuff you like (TV shows, books, games, etc.)
* Encourage who she is (follow your passions, be strong and confident, etc.)
* Encourage talents (you should be able to see them there, give her suggestions on what to do)
* Money (how to invest, save/emergency fund, net worth, save for retirement, keeping up with the jones, etc.)
* General advice like (top 3 reasons people get a divorce .. money, sex, religion)
* General tech advice (password resets, no 2 passwords the same, once online always online, etc.)
* More general stuff about the world around her (world economy, driving in your area, etc.) anything that you would tell a kid during their lifetime.