Is my old girl dog going through anxiety separation?

we gave her away after being with her for 6 months (we got her and a guy (so their brother and sister) we kept the guy and gave away the girl cause it was hard taking care of both of them. we gave her away to a family friend (he has 5 guy dogs (same breed) and he said he wanted one girl) so yeah he has him now and he updates us about her. he told us that she's skinny (she doesn't eat much) and she DOES NOT get along with the other guy dogs. the other day, a guy dog went near her and she bit him and wouldn't let go. she's always alone and in the corner and no one goes near her (so basically she's the boss in their territory) btw. all these dogs are jindos. my GUY DOG is perfectly fine. he doesn't whine and gets along great with people and dogs. when we had her, he was the boss and she was always submissive towards him (well if he bothered her she fought back) and stuff