Green Card Lottery visa question - please help!

[irkin77]

hi,
i have a question about the procedures on the green card lottery winnings.
a couple has filed for lottery, and wife has gotten a visa. they have a 8
months old daughter. after their interview in American embassy(in Warsaw),
wife(who was the primary winner) has received a visa as well as the baby.
however, her husband is still waiting. they never denied him, but they still
say they are checking his background. it has been almost 6 months since the wife has gotten her visa, and her deadline for entrance the USA is coming close. do you think there are any possibilities to extend her visa until her husband gets his visa approved? how big is the chance that he might be denied? if she decides to immigrate alone(with the child) without waiting for her husband, how and how soon can she petition for her husband here?

if anyone has experience something like this, please share your info.

thanks so much!