The Children’s Online Privacy Protection Act (COPPA) is the best choice in this context, as it specifically addresses the collection of personal information from children under the age of 13. It imposes certain requirements on websites and online services regarding how they handle the personal information of children, which would include protecting Callum's daughter's information when he creates an account to buy soccer cleats.
However, it's worth noting that while COPPA focuses on children, other laws and practices may also protect Callum's personal information in general, such as the use of secure transactions and privacy policies.