My 6 mo old girl was exposed to chicken pox at her daycare at least twice. Doc is recommending giving her the vaccine now. Does this make sense?

No. Chicken pox vaccine is not recommended to the infants under 12 months at the present time.
Yes. Normally your daughter would not be vaccinated until age 1, but since she's been exposed to the virus it makes sense to vaccinate her now. The vaccine is about 90 percent effective in preventing chickenpox if given within 3 days of exposure to a person who has chickenpox. Even if she still gets it, after immunization it is likely to be much less severe.