A lot of games you buy are designed so if you transfer them to another computer you will need to re-activate them on that new computer. This is to prevent theft and other from giving out the game for free, which impacts negatively on the creator (since that's their income).
You will need the product keys to re-activate your games.
If you bought the games from Big Fish Games, then it should be in your purchase history on the site so long as you or your Dad had an account with Big Fish at the time of purchase. Otherwise you will have to comb through emails for the order receipt/s for the keys.
The only other way that may be of some help is contacting Amanda herself about your issue, but then she may want proof of purchase still.