Newborn tiny for car seat

I put muslin blanket on the side to support her neck..

I mean, no, not really! Isn't there an head insert for newborns with your car seat?

I bought this & it works really well. https://a.co/d/1a9PHqm

After market inserts aren’t safe for car seats. Use whatever came with the car seat. If one didnt, call the manufacturer… they might be able to send you something. Look for chin to chest, that’s where the concern is for breathing. Also join CSFTL for more advice!!