Chicken pox or MMR rection - either way how contafious???

[Ab31]

My DD (12 months) and I are due to spend Christmas with my sis and nephew (4) who has today come out in spots all over. We reckon its either chicken pox or a reaction to the MMR booster. Either way is it contagious? DS says that with CP, once the spots appear there's no risk but I don't know if she's just saying that...! Or if it's MMR measles is that contagious to babies? She hasn't yet had MMR...
Confused!
Thanks!

It should be fairly easy to distinguish between the 2! If Cp spots are contagious until scabbed over. Personally I wouldn't worry about chickenpox exposure unless I had a particular reason to as she will get exposed to it at some stage.

MMR reaction supposedly shouldn;t be passed on. If it is it would only be the same thing as she'll be getting very soon anyway.

Yeah but at Christmas???!

the MMR reaction is 100% NOT contagious!

well it takes 14 to 21 to incubate iirc so won't be at christmas.