Plenty of kids with pianos and parents musicians grow up not being child prodigies. But, pretty much no child prodigies grew up in environment where people don't listen music much, without access to piano, teacher (official or unofficial) and so on.
Unless the parents lie and literally manufactured it all, both components needs to be present. For most 13-15 years old, just focusing on one big project and keep interest is quite unusual. So is willingness to build one thing for so long.
Plenty of kids with pianos and parents musicians grow up not being child prodigies. But, pretty much no child prodigies grew up in environment where people don't listen music much, without access to piano, teacher (official or unofficial) and so on.
Unless the parents lie and literally manufactured it all, both components needs to be present. For most 13-15 years old, just focusing on one big project and keep interest is quite unusual. So is willingness to build one thing for so long.