Technically, they usually have 30 days to file for an appeal. But I don't know if that is still the case. Practical, helpful steps for you to take: the clerk of the immigration court has everything you need, so visit her. If the govt appealed/did not appeal, that information is with the clerk of court. Visit the clerk and ask for your case file. She can make copies for you. You can check if there anything from dhs about appealing.
I don't know about deadlines these days. Everything is super slow, so perhaps the judges are permitting dhs to take millions of years to appeal?