My babies are doing great with bonding. Surprisingly good. But they both kind of have the same issue; they bite. Sometimes it's the friendly 'hey there' curious bite, and it almost feels like they're just holding your skin in there teeth. Other times it's the significantly hard bite; won't break the skin, but it's enough to make you wince and say 'ow'!
They've never broken the skin, but my girl came up and sat herself on my shoulder when I took them out for the second time in the bathroom. I was surprised, because she was so shy. But then she went up to my ear, and bit it! It was pretty hard, and not even a few moments later she bit my face. I took this as maybe just her being curious because it's the first time she's seen me with my hair up, maybe my earrings (I have two in both lobes) or maybe the scent of my makeup. I tried to make the small sound everyone recommends, but did say 'Aye!' the second time. I was just stunned, because this was my first time being bitten.

Can someone explain this to me? Or is this just her being a typical glider? My boy has never bitten really, just licks my finger and nibbles it, but it's never hard.

I'm glad to hear it's going well.

Biting is something gliders do sometimes, and for different reasons. I haven't had joeys, all of my gliders were a little older when I homed them. So I haven't had experience with joeys.

It could be testing, it could be the scent of your makeup or something else that you're using. I really cannot say, either could be the reason. Maybe someone who has more knowledge of reasons gliders will bite will have some answers for you, but I wouldn't think it's abnormal for joeys to bite while in process of bonding.

The severity of the bite and other behaviors going along with the biting will give clues if it's meant as defense which can seem quite vicious to us, but is truly just their defense. Which the latter being mostly my experience having homed adult gliders. My Lulu was cage protective (defensive) and would attack and bite very old, while my Skadoosh would give a timid bite here and there as if saying "hey I don't want to be held", which is now what I get from my Lulu since we've built a relationship over time. My Ollie, well he's a nipper, not really sure about his, probably a bit of a protective bite, but kind of like a test as well. He is my eldest glider and has had a tough time of it in his short 4 years. The mom I homed him from was a good mom, and told me of his past, as she took him in as a rescue. So he's had good experience with people prior to my homing him. My girls were, well pretty much ignored after their first few months in their first home, only cared for by their mom, then pretty much left alone.

I really should have said they're both around 4 years old

It's more so the same case; they were never really 'bonded'. The previous owner just cleaned their cage, put food in there and only took the boy out when someone wanted to see them. The girl is timid, so he didn't even try with her.
The biting is better now, but I've also been leaving them alone besides feeding them and giving them their mealworms. I figured they needed their space.
The bonding pouch has helped a bunch too. I put a slice of fresh fruit in the pouch and wear them for a good portion of the day. I stayed home from a camping trip to bond with them alone, so I get them in the morning and lay down on the couch with them while watching T.V., softly petting the pouch. When I open it up to pet them from time to time they do wake up but don't shy away, crab, or bite me.
Another question; should I be concerned that my female freezes sometimes? She won't move a muscle, not looking at anything or anyone, she just.. Blanks out. I'm scared this may be a seizure and I'm trying to get a appointment with the vet. Problem there is my phone is off at the moment and like I said I'm alone all weekend because my family went camping. I'm also fairly young, so my mom needs to make the appointment. I'll be telling my mom tomorrow as soon as she gets home but does anyone know what this may be?

She might be hearing something that you can't or a self defense mechanism. Sometimes my Kiki will do the same thing, especially if I move too quickly. But it never hurts to have a vet checkup just in case.