Is this baby acne ?

Chanie • 26 year old model from London , first pregnancy and couldn't be more excited !!!!!

My little one is 3 weeks old and has had this rash for a few days. Some days it looks worse than others and its spreading so fast. Its also on her neck , above chest and this morning I noticed a few at the top of her back. Is this baby acne or something else and what can I do to help it go away ? Thanks