What should I do about my friend?
So I have this friend. Her nickname for now is "SS". So me and SS have been friends for just shy of a year and I really enjoying being her friend. But there's a problem: she was in another friendship group while also being in a friendship group with me and my other friend(E). I remember finding out that she was in another groupchat and asked her about it and she said that she only left because I added someone she didn't know-I did try to introduce my friend to her but she just refused . After that, I just forgot about the situation and actually started to hang out with her group(at one point I actually wished I was in her group). Something that she and her group did really upset me: it was my birthday and was excited to receive my gifts. When I arrived, 2 people(SS and another member of the group who we'll call Blonde) don't have anything for me. Only the other 2 members got me something and one of the gifts was decent but not the same for the other members when it was their birthdays. And on the day of my birthday, we got a week off(a break) and when I came back SS gave me a medium sized bag but it wasn't even half full. It was sloppy and looked rushed. Even the card was big but hardly had any writing in it. As for Blonde, she got me a very small card and 2 stickers. However(Orange- the one who got me a decent gift) got loads of gifts like a teddy bear from SS and loads of stickers from Blonde. Also, (not relating this) I was tired and was therefore visibly upset. SS sits across from me and I'm pretty sure she saw me multiple times, looking upset, yet she still didn't say anything. Only one person asked if I was ok and I said "No! Does it look like I'm ok?". She gave me a dirty look and then just continued to talking to the group, continuing to ignore me, all of them. Anyway, skip forward to these past few weeks. I decided enough was enough and confronted her (on paper because I was too scared/shy to do it in person) and she didn't reply. She didn't even send a note back or talk to me about it person(I have a feeling she knows what I wrote was true and doesn't want to accept it). After that we have still been talking but I still have thoughts that she is not a good friend or perhaps a "fake friend", like other people told me? I don't really know what to do especially since our 1 year friendship anniversary is coming up. Should I tell her straight (again)? Please give me any advice you can