I'm scared my children will be alcoholics

Alcoholism run in our family. I have been sober for 5 years. My children's dad is sober for the 3rd time and he's been sober for nearly a year. My daughter turned 21 back in July and it seems every weekend I look on her Instagram and she's posting with a drink in her hand or has a friend over and they are drinking. It doesn't seem to be interfering with her life too much. When I call her during the week she sounds sober. She's sent me her report card from college and she's bringing in mainly A's and B's with one C in Chemistry which I can't blame her for. I was terrible at Chemistry too. She's in college for nursing. At the moment she works as a medical assistant Mon-Fri and she said work has been fine. I understand she probably wants her weekends to relax and not have her mom up her ass about it. It just scares me because I made her and her brothers life really hard because of my alcoholism. Her brother is 19. He got married to his now wife at 18, they just had a baby and he's at a trade school for welding, which he's doing good at too. His wife is 21 so I'm sure she has gotten at least a beer for him to drink. As far as I know he doesn't drink much. The most I've seen him drink was a beer his wife got him and thats it. My kids have both turned into very respectful members of society but I just can't help worry they will go down my path. So whenever I see them drinking I just want to yell. But they are adults now and I have to let them make their own decision. Its just scary