What is this?

Ta

So my baby is a little over a month old and she has this rash on her face it started on just her chin and now it's spread over her whole face and has started on her next and behind her ears can anyone tell me what this is? It doesn't seem to bother her and she doesn't have a fever but I am concerned if it doesn't go away soon or if it keep spreading I plan on taking her to the Dr it's kinda hard to see but it's more red in person