NTA

You’re being a parent. Who else is supposed to teach these life lessons to their children? Having kids myself I’ve learned the whole “all kids are different”. You know your kids’ level of maturity and understanding better than anyone on the Internet. Based on my own anecdotal experience, 12 is definitely old enough to learn how to save money. It’s a life skill they won’t learn in school! Same with budgeting and other personal finance stuff. Keep being a parent! We need more parents doing parent things!