Advice please as im now freaking out!!

So my MIL was messaging me and I sent her a pic of my little girl with her new blanket in her cot, and she was drinking her bottle. She said just make sure to take the bottle away after because she can choke and her partner sister died like that....

now I’m panicking because I thought at this age it would be ok to leave her so many times since she’s been on cows milk I’ve given her one during the night and dozed off before she’s even finished or gone back to sleep I feel like she could have chocked and I wouldn’t know!!!

Have I just been really careless? I feel like such a bad mum now that this could have happened! I truly thought she would be ok to be left at this age 😩😩