Chicken Pox Risk in Adults: Understanding Incubation & Prevention

Question
HI!  My 50 year old sister never had chicken pox.  Her 60 year old husband has shingles.

What is the incubation period, plus odds that sis will get chicken pox.  

Is there a test to confirm her chicken pox lack of immunity?
Is there any vaccine she should take to prevent or lessen the impact of the C. P.?
THANK YOU!

Answer
What is the incubation period, plus odds that sis will get chicken pox.  = 7 days

Is there a test to confirm her chicken pox lack of immunity?  = no

Is there any vaccine she should take to prevent or lessen the impact of the C. P.?
= can get immune antibodies if hurries