My friends 60 yr old mother steals all the time,uggs, electronics etc for her kids and grandkids and herself!?

I have no idea what to do, they will not talk about it but I know and have seen things such as hundreds of dollars worth of american girl items, hollister, keen, north face, pottery barn, etc. She is a professional, how do I go about this, I have known them for a long time and was always wondering how they could afford such items, but never had any proof, I mean even her grandkids know about it and thrive on knowing that their grandma will get them whatever they want, I mean I know they need serious help but how can I report this? Please help!!!