Congratulations, you've somehow acquired a Gwen! Perhaps that should be condolences, but either way, you'll need this guide. The Gwen is weird and tends to be contradictory, but will absolutely blossom under the right touch and is worth the work of caring for.
1. On friendship: this one's pretty variable. If you've acquired her as a friend, go gently. She likes you (trust us, you'd know if she didn't) but her needs may vary from frequent in-person contact to infrequent and erratic chats via text or messenger. She's unlikely to suggest getting together, because she often doesn't think about actually seeing other people (introverts, y'all), but will probably respond enthusiastically should you suggest it. If she doesn't, don't be discouraged; she may have used up all her emotional spoons that day and simply need alone time. If she does suggest getting together, she views you as important, period.
2. On habits: the Gwen picks up random habits (vaping, going to bed at a specific time, talking a lot, scratching her butt) and doesn't break with them easily. She's a creature of habit. If you are trying to break her of one or more habits with regards to either herself or you, be kind. She may get scared.
3. On brain chemistry: she has both clinical depression and anxiety disorder. She'll have good days and shitty days, and 99% of the time they'll have nothing to do with you. Please do not take it personally if she is silent one day, or grumpy, or sad; she'll be better eventually. Do not under any circumstances utter the phrases "just get over it" or "just calm down." This summons the Redheaded Bitch.
4. On communication: she's overly honest and open, or she's completely closed off. She may talk to you once every six months, or once every few weeks, or a lot. It will depend on several factors, including level of interest, type of conversation, and whether the stars align properly that day. She may dispense personal information right and left while sitting on how she feels about you, or something you've asked her about, or she may not.
5. On seduction: she'll figure out you want to sleep with her when one of two things happen - if you are actively kissing, fondling, and undressing her or if you tell her "i want to have sex with you." If she responds enthusiastically, great! If not, don't push. It's rude.
6. On dates: if you would like to go on a date with her, your best bet is to tell her this directly - preferably with enough lead time for her to adjust (her default assumption is no romantic interest until otherwise stated) but DO NOT GIVE HER ENOUGH TIME TO OVERTHINK IT. Just don't. Four days' warning is usually good. Hints such as "i need a girlfriend who isn't flighty," "we need a girlfriend," or "i like dates" don't work. She will sympathize and continue being oblivious. If she says no, accept the no. She'll just keep saying no, with increasing irritation levels, if you push.
7. On romantic interest: she is clumsy and often blind to her own and others' feelings. If you know her well enough to actually love her, chances are she feels the same way and either hasn't acknowledged it or hasn't said anything because she assumes friendship until otherwise stated. If you express romantic interest and she indicates that your interest is not returned, accept it. To do otherwise is to expect her to produce emotions she doesn't feel, and that isn't going to happen. She will do accept it if she expresses romantic interest in you and you tell her you aren't interested, trust us.
8. On moods: your Gwen does have a temper. If she gets overly snarky (not to be confused with normal snark levels, wherein she's generally silly and sarcastic), verify she's had enough food, sleep, caffeine, and nicotine lately. If necessary give her alone time. She will recover and go back to being sunny.
9. On affection: she loves it. Pet names, pets, cuddles, kisses, being told you care, all of the above are 100% good all day every day for as long as you feel like doling them out. Assuming she's comfy with you invading her weirdly flexible personal space. Keep in mind that spurts of affection interspersed with little/no expression of affection may result in her anxiety going haywire because she's unsure which side of that equation is accurate.
10. On fear: the Gwen has several fears. It goes with the territory of depression and anxiety. If you inadvertently hit a fear-trigger and she misbehaves, gentle but firm reminders that she's safe, you care, but the behavior is unacceptable will correct her behavior. If treated harshly, she will retreat into silent confusion and often wind up afraid to even bring up situations that bother her.
Good luck, godspeed, and remember: if cared for properly, your Gwen will be a loving, understanding, infinitely patient companion.