[US] Romance Scammer Targeting My Mother

I really don’t know what to do in this situation, and I was letting stuff slide before but now I’m desperate for advice.

So, first off, I’m a minor (17, 18 in April), so I don’t really have any control over what she does but that also means she’s my legal guardian and thus this will affect me too. Plus, we have section 8 so this is especially bad for us.

She met a romance scammer on Facebook (he had all the signs, like taking the messages off of Facebook, asking her to download third-party apps to give her money, saying he was an engineer working on an oil rig so he couldn’t come see her, etc.) Even I didn’t realize for a while because I was excited for her and for us, but once I finally figured it out, I told her to delete all those other apps and say she would not send him any more, which she did. After that, everything seemed harmless enough and she even acknowledged he probably wasn’t genuine, so I thought it’d be okay if I didn’t push her to stop talking to him.

But now she says he wants to send a six digit check and have her send 1000 out of it back, and even though I had her promise that she wouldn’t do anything with the money if it actually came until she talked to her bank about it, I heard her say to him on the phone that she can’t put it in her normal bank account because they’d tell the state about it. So I think she wants to actually take it and send the 1000, and keep it in something else, which I’m really scared about because I’ve heard about scammers sending checks and then taking the money back after the person’s used some of it, or the check bouncing after they’ve used it and leaving them in the hole, etc.

So, I need some advice on what to do. Do you guys think there’s any way I can get her to listen? What company or organization can/should I talk to about this?

Edit: Thank you all for the advice and resources you provided! I told my siblings about it, and also told her all the information you all told me, so I’m hoping that she listens, but if she doesn’t, one of my siblings has said she’ll talk to her with more provided info, and if she doesn’t even listen to her, I’ll call adult protective services to see if she’ll listen to them instead. I also had the idea of seeing if I can find and get her to try out some ways of making some friends.