Oct 2, 2016 - 12:48 PM
Hi donnynoypi, welcome to MySwissAlps!
You and your wife each need a Swiss Half Fare Card. I'd recommend to print those yourself along with the Swiss Family Card. That will be quicker than going to a staffed desk with the passports of all four of you. With the prints, you can skip that and get your discounted tickets straight from the ticketing machines. Here's how to do it: please visit www.swissrailways.com/ en. After filling out your address, they will show the delivery options. Pick "Online Ticket" from the bottom of the list. They will e-mail the cards (no delivery fees) within 1-3 business days, so you will need to order today in order to use them on the 6th, or no later than tomorrow in case of the 7th.
Note that it takes at least 4h15 to reach the Titlis from Geneva. It will be a very long day, mostly on trains.