No, you can only have one sponsor. If another parent wants to have the ability to send you money, they can sign up as an adult and get their own StoreCash bank account. Once they do that, they will be able to send you money anytime, but note that they will not have any visibility to the teen account or track your spendings.
*StoreCash is a financial technology company, not a bank. Banking Services are provided by Piermont Bank, Member FDIC. The StoreCash Mastercard Debit Card is issued by Piermont Bank pursuant to a license from Mastercard International and may be used anywhere Mastercard Debit cards are accepted.