The Moneyist: ‘I just don’t trust my sister’: How do I gift money to my nieces without their mother having access to it?

Dear Moneyist,

I am a devoted aunt to twins. This year, they are turning 13. Their mother and I have had problems in the past. We are sisters and fight like sisters. But I’d still like to be able to gift the kids monetary presents as they grow up. I was thinking I’d like to give each kid $500 this year. 

But I’m worried about their mother having control over the money. I just don’t trust my sister. She has a history of spending recklessly. I’m also concerned that if we fight again, she might tell them, when they are ready to…