No . You can stick something under the mattress to slightly prop them up if there’s an issue laying flat . My daughter had stomach issues so the doctor recommended doing that & it’s helped ever since .

My baby had a nasty cold #winterbaby she couldnt sleep because he was so conngested so i folded a blanket still yet confy and she will nap through it but I did keep an eye on him and it was during the day

No, blankets, stuffed animals, and pillows are advised to not be used until 1 years old.

No.

no, she’s to small to sleep on one she can roll over and get her face stuck on it and not be able to breathe.

No, it’s not safe for babies. They can roll over and get their face stuck by it, and not be able to breathe.