I have two young ones, one female and one male roughly a few weeks apart in age from one another. for weeks I have been trying to be able to open up the cage they are in. (a ferret nation with a ramp clipped up to create two parts of the cage) when I first started they were fine for the most part. your normal squabble and so on. but now my female is hissing a lot and even when she cant see him or someone is holding him. they would normally go at it when they were playing (never any blood or anyone pooing themselves) but now she just follows him around the cage hissing and biting at him. the only time the cage is not open is at night. other wise all day when im home its open or they are out playing together. is this normal for them to take so long to figure out who is the dominate one. or did I pick one of the few that does not get along with some other ferrets. Or has she become territorial over the things she thinks are hers. she will go down and eat or drink out of the crocks he normally uses and she also has use the larger litter box (he wont use the small ones he is a big boy) and even fallen asleep on his blankets, just not with him. any incite will help.

She may just be territorial, and there may be nothing you can do to get them to happily live together.  Continually forcing her into living in the same cage with him is just going to teach her that you're against her, and she really does need to show her displeasure to him, because you won't help.

Luckily, it sounds like they are fine when out of the cage together?  With a ferret nation, keeping them in separate living spaces is really no big deal.  I have a ferret like that... he stays in the top half by himself (although, he has decided that my newer male is awesome and can live with him) and the others all live in the bottom half.  They come out to play together and everyone is happy.  Then at night, they go their separate ways, and everyone is happy.