I've had ava for 7 weeks. She came from a home with mom dad and a sister. She is significantly smaller than Fifi. I got Fifi about 5-6 weeks ago. Introductions where rough at first using pouches in the tub.We took the pouches out and had a sweet introduction! After awhile I notice they get annoyed of eachother though. So it's been about a week since I got them a new nice big cage. Hissing at night has gone on for while and I didn't really think anything of it as I thought they where just talking. Lately they bicker and chirp more but it sounds aggressive like it's going to break out in a fight so I usually get up right away with one and play with them seperatly until they calm down. When eating FiFi grabs Avas hands AND BITES THEM?! Ava prefers to be snuggled up with momma than in the cage with FiFi, almost like she wants to get away from her. During the day they cuddle and sleep together in the same pouch. I have seen them groom eachother before. I just don't know if I'm being over protective and I should let them work it out or if there is something I should be doing for my babies?Should I separate them or will that cause more stress? I would be so heart broken should something happen to them.

Whenever we feed the gliders treats if one does NOT have a treat, instead of waiting his turn he will simply go after whatever is in the hands of the other. they are not trying to bite the hands, but instead trying to steal the treat.
If getting corn out of the food dish, a glider "they love it special", they will run into the corner and eat the corn so hopefully the other gliders don't steal it from them. this sounds like what it happening to you.

We have sleeping pouches containing 7 and 4 gliders. at times during day and night, the gliders bicker, a squick, squack, spit and spat. It is usually short, but sometimes lasts a few seconds. majority of the day they sleep quietly.

Sounds like you did introductions slightly fast and not following all the rules. BUT sounds like they are together in the cage and ok. If they fight I would separate. At night in the 7 colony we have one small female that will sometimes chase a large male. the large male makes a horrible loud shreak to try to keep the small female away. I will sometimes make the female go away. they dont do this as much anymore. I would keep an eye on them at night, if they are NOT fighting, I would let them stay in same cage. watch for fighting and chasing. We did a introduction to 10, one female was chased by any 3 in the colony to the top corner of the cage, she was the nicest female very sweet, but after several nights of chasing (they slept at daytime together just fine) we had to remove the female.

Thank you so very much for the reply!