My mom told me earlier this week that my niece (almost 19, going to CC, no job) came into some money, not a lot but a decent chunk recently and my mom had her put the majority of it into savings for when she transfers to the state university next year. Because my mom is the co-signer on her bank accounts, she can see all of the transactions and my niece has already blown through over 3/4 of the money in less than 2 weeks. My mom doesn't want to bring it up because she thinks my niece will feel like she's being spied on and my H thinks I should talk to my niece about what's going on - which would obviously rat my mom out for checking her accounts. Our biggest concern is that my sister has manipulated my niece into buying her things but we can't know that unless we ask... So what would you do?