Hi my 8 month old has a rash over her entire body, it's pimply, been there all day, but seems to have spread more, she seems fine, but I'm worried : (?

Virus or drug. Most common cause of such rashes is a virus. Lots of viruses cause them, not just the well-known ones like measles and chickenpox. 2nd most common cause is a reaction to a medication. Probably not anything to worry about, but if it continues to spread, call your pediatrician or a dermatologist.