Newborn baby and chicken pox

Hello,

My little girl is 18 days old today and I have just found out my nephew has chicken pox. His spot came out yesterday but my little girl was by him Saturday evening. Anyone else experienced this at a baby's age. I've been told she should be protected by my immune system for her first 2 weeks but I'm still worrying. I'm going to call the doctors in the morning to see if they can give me any advice as I believe it can be dangerous if she catches it within her first 4 weeks. Any advice would be appreciated thank you