I got cholestasis during my second pregnancy with twins, but not my first with a singleton. What are the chances of getting it again?

Increased risk . Cholestasis affects 1-2 per thousand pregnancies & is more common with multiples, women with liver disease, or if primary family members (mom, sister) also had it in pregnancy. South american women seem to have an increased risk. Recurrence risks have been reported to be as high as 90%. So, don't have twins again! (do let your doc know if you have the same symptoms with your next pregnancy).
High. Based on an admittedly very small sample. I have always seen it recur in subsequent pregnancies.