Given the number of comments made so far, the odds that the OP will see this (or more than a handful of people, for that matter) is vanishingly small. That said, I laude you for your creativity and insight to do such a thing for your daughter. You might want to do something similar for your wife, as well; I expect she will want to hear encouragement from you, even after you're gone.
My father passed just under a year ago, due to complications from stage-4 Non-Hodgkins Lymphoma. There was about 10 days between his diagnosis and when he died; he didn't have a chance to make any specific goodbyes. Admittedly, my situation is different -- I'm cis-male and my father died well after I became a (nominal) adult. However, I can offer suggestions based on what I would have liked to know, and never had the chance to ask. I can also offer some advice based on the efforts my brother and I have had to go through to deal with his papers and documents.
I'd like to have had more records of my extended family and those who came before. My father was a first-generation American, the child of Holocaust Survivors. I don't know that much in the way of specific stories about my family from Europe, or the struggles of leaving, my grandparent's emigration, or similar. I know my father (and uncle) had stories told to him by his parents, though. Few, if any, ever made it past that; I hope my uncle will pass on the verbal record as he best can.
I'd like to have known more about my father's life and who he was. In going through his papers, I've found letters of commendation from Under-Secretary (US Cabinet) level offices about subject I had no idea he had any expertise. I never realized how many patents he had gotten over the years (none of which were software, FWIW), or some of the weird adventures he had. I know he was a prankster when he was in college, but I didn't realize the extent until I found a letter from a college friend that read like an indictment. =)
I'd like to have known more about things he wish he could have done and any regrets he might have had. I know he never visited Israel and wanted to, but little else. I can't right any mistakes he made, but maybe I can make some sort of amends or do things in his memory.
I would like to know what he would have thought of any kids my wife and I might have. I personally regret not telling him that we plan on having kids -- I think he died thinking that my brother and I were the last of our line (My brother has no intention on having kids, only cats).
Give whatever advice you think best. You know your daughter, and while she will change over the years, the best you can do is to be honest and frank. Inevitably she's going to fall; give her your advice on how, somedays, the best thing is to get up and fight back and others it is to eat a pint of ice cream and fight the battle a different day. Someday, someone is going to violate her trust; give advice on both how to rebuild that trust and how to walk away.
Perhaps my strongest piece of advice is don't make videos for specific events. Make videos for types of events, and maybe for different ages. She may or may not ever marry, graduate high school or college, or have children; make videos for days of celebration. She may or may not ever lose a partner or close friend, have a divorce, get into a car accident, or fail a class. Make videos to cheer her up after a bad day and encourage her for future endeavors.
Regardless, make sure you let your personality come through; don't get so caught in the effort that you miss the most important message.
Some advice on the non-video aspects, though. Go through your papers (or files or whatever) and trim them down to what is important and what isn't. I didn't need to find 2 dozen copies of my father's Thesis, or his college notes, much less his stacks of punch cards (... which were unnumbered. There's a special kind of hell for people who don't number their punch card stacks). Nor did I need his collection of square-dancing ribbons (hundreds). Letters from him to his mother at camp, a family tree, or a 'camp' songbook from the friend-his-parents-warned-him-against? Those are the things that are treasures. Relevant financial records, not a stack of correspondence about whether someone sent him a check or not 30 years ago. Label photos of important people or places, and trim the rest. Especially if no one else will recognize the items in the photo. Make sure heirlooms are documented to the best of your ability,
And put your passwords into an escrow, so that anything new isn't lost or forgotten.