DV lottery eligibility

My girlfriend is Moldovan on F-1 visa in the USA and she has 5 months of J-1 requirement left from her previous status (J-1).

I was wondering whether she is eligible to apply. I am thinking that if she did win could she go home for 5 months satisfy the requirement and then apply right away?

In other words, do you have to be eligible at the time of application of the DV lottery or at a time when you actually apply for change of status?

Thanks.