Night Bite

Hmmm… she’s purring so she is happy that you woke up and can now give her some attention ! Most cats wake up sometime during the night to potty, “hunt” or otherwise prowl . They can “train” us to get up and keep them company, too! Do you pet her or reward her in some other way when she does this ? ( If you do then stop !) She needs/wants more attention from you - establish a regular evening play time of 10-20 minutes that includes jumping , running, twisting & turning ( for her - not you ) and give her a good “work-out”. Until she learns that bedtime is not playtime you may have to banish her from the bedroom or sleep with a spray water bottle.
She bites bare skin because that is what works ! My 10 month old loves bare toes and will dig in the blanket to find them ! Which is a major problem because I find sleeping with my feet covered uncomfortable. Fortunately , I have a “guard cat” for the bed ( my 16 year old cat doesn’t like the young one to sleep on the bed ), but if I try to sleep on the couch I too suffer from night bites if I don’t make the young one sleep in “her ” room.
Again - give your cat lots of attention in the evening. Spray bottles are effective but are also very uncomfortable sleeping companions.

My 9 month old kitten Alissa does the same thing. We have a walk in closet that has a door on it with windows so she can see out. My husband and I put her in there, which is where her food, water, litter, scratching post, and bed are located. She does it because she wants to play or get some love. When my husband leaves for work in the morning, I let Alissa out and she comes on the bed and cuddles with me. My husband does not like her on the bed with him. But I allow her on it when he is not home. Try to put her in a room where she is not going to bother you while you are trying to sleep. Make that a routine thing and she will sleep during those hours too.

I think she bites because she wants attention. You shouldn’t pet her after she does it though because she will keep doing it. You should give her lots of attention before you go to bed and if she bites you, spray her with a spray bottle.