Its rare to get it twice ,but possible, i came out with the spots the day after i was born due to my mum having it when she gave birth, my doctor continued to call me as the "chicken pox baby" until he retired as it was first, and only time he had known a baby to be born with it lol, i had it again when i was about 14 and was warned to be careful in future as if i came into contact with the virus in the future as it could come out as shingles.Hope your little one is ok and not feeling too poorly no mater what the cause x