As someone who will lose his father in the next couple years, there aren't enough mod points in the world for the parent comment. Go do things together. The memories of doing stuff together are more valuable than any amount of messages he could leave me. I've watched his health decline steadily for the last five years, knowing that eventually it would kill him (and since it's genetic and I'm also a carrier, it'll kill me in about thirty years as well), and I've realized that I wouldn't trade the memories - vacations, fishing, hell, even building fences - for anything. I live about a thousand miles from my parents at this point, but I still make an effort to talk to them at least once a week and spend a few days with them every month or two. His breathing has now gotten bad enough that he can't travel, so I'm glad we did so much while he was able to get out and do things.
I'd spend time with her now while you're still in good condition and able to do so. The months of watching you get worse are going to be very hard for her, and the memories will be worth their weight in gold. Don't delay until you're too sick to make it happen.
If you want to leave her with a few thoughts, I'd write a letter or two. Those will be far more durable than any digital form, and will be a tangible object to tie the memories back to.