Did my mom steal my money?

I'm in college and I had a refund check send to my moms from financial aid. It was for $1500 and they told me to put it away for the summer/ fall semester. My moms a alcoholic and I'm afraid she kept the check here's our conversation (and she won't call and talk to me). On Thursday: Mom: I had to resend ur envelope, I wrote the zip wrong, I paid to over nite it, it will get to u tomorrow Me: Okay thank you. Did you put 1****? Mom: Yes, this time! It came back to me, this time I had the post man do it... Yesterday: Mom: You get your envelope? Me: No Mom: Wat!! It Was supposed to get to u Friday! !!! I'm going to the post office tomorrow I should have sent it so u had to sign for it omg there's a check in there! Me: Yeah I don't know maybe check with the post office tomorrow Today: Mom: They said they can't track it, must b late...check today! Resend your address please I still didn't get it today. Is it possible she kept it?