I don't know the answer, passing on the question to my followers. :)
Just one idea: Since it is for a baby, it should(?) be made of cotton, so it can be washed in a better way.
There are different cotton yarn qualities, some of the more expensive ones probably last must longer, but I am not an expert. :)
@thegiddystitcher @knitting
:) I wish you luck when researching the topic โ and a lot of joy when making this sweet doll. ๐