Baby will NOT sleep when lied down 😩

I’m a desperate first time mom—HELP!

Husband and I have struggled these past two days, ESPECIALLY night, because baby girl (who is 4 days old) will sleep no problem when being held but the moment she touches her crib, she wakes and cries and fusses.

When my mom has her, she places her on a soft, thick blanket and in that baby sleeps just fine!

I would do that, but isn’t that dangerous? Aren’t infants only allowed to sleep on a FIRM mattress and not on something soft like a light pillow or blanket?

I don’t know what else to do! 😞 my mom is insisting to use a blanket/pillow so it’s soft and warm around her but I just don’t know. I know this is all a learning process, but we’re drained. Please, advice!