@chel86831 When a game or pack is bought directly from EA, there is typically no product code provided. Instead, the content is added to the purchasing account's game library.
In general, the only way to add content to a child account is to purchase a code from a third-party seller and register it to that account. In this particular case, since you had no intention of using the content for yourself, you may be able to convince an EA customer support rep to transfer the pack to your daughter's account instead. I would strongly recommend using live chat rather than email. If you don't see the option, try this link:
Make sure you're signed into an EA site (this one is fine) before clicking the link and that the location in the lower-right corner of the browser window is set to U.S. or U.K.
