How To Deal With This Problem? Friend Help?

Ok so my “best friend” is odd. Give your input on each problem. Her name is Jen. She doesn’t have a phone she uses text free on her touch i really need some help. i have already talked to my mom about some of this. My name is Melissa.
1. She invites her friends over. They are twins and I know them. And I text them a lot. She goes to my house and asks to play with them there. We go on my trampoline and they compliment me a lot on my house and my yard. The twins were like “You are so lucky that you have a trampoline and a pool next door (my neighbors pool).” So we play and then they leave. Then i got the other twins number and we were texting while they were at Jen’s house. Then while i was swimming Jen texts me and asks to play, The twins left and i said i was swimming. then she says can you do me a favor. i said what is it and she said “don’t text MY friends that you don’t really know.” i never answered. Then we played after dinner and i go home and she says ‘can you answer my text?” The one referring to texting her friends that are also mine.
2. this also connects to the next one
Jen calls to play from our neighbors house Christina at like 7:30. i say i can’t then my sis gets on the phone and listens in on the conversation. Then she says “oh yeah i forgot you went to bed at 8.” When i don’t. So my sister talked to me about it and gave my advice.
I was on the trampoline with my baby neighbors and Jen comes around to play on her bike. i say i can’t but she says my sis (21 years old) said “i could” when she didn’t. So she leaves and i go inside and tell my sis what happened. Jen goes around again and my sis stops her and talks to her and says you shouldn’t be saying stuff that isn’t true and talked about the bedtime incident. She cries and goes home and her mom calls my mom. They talk, and Jen’s mom says “i know Melissa’s sis can be mean” My sis is really nice and all my friends agree except Jen. and her mom says ‘ i don’t want Jen going over with just Melissa’s sis home”
3. we went to a home run derby together and she doesn’t really know the winner named Ben. when i get home she texts me and says ” i texted Ben and told him that he shouldn’t have won” i said how did you get his #. she says why do you care? i just wanted to know how she got his number. she keeps saying you shouldn’t be worrying about who i text and why. I just wanted to know how she got his number.
4. She asks for my phone and i give it to her. she goes through my contacts and says oh you don’t have Paula (our bff). i did before i handed it to her. And then she goes you don’t have sami her friend that i met. i did before i handed it to her, so i added her back on and gave it back which was a bad idea. she deleted her again i think. I don’t know if she deleted her or it just magically disappeared. well when she gave it back, her friends that i met were all gone. when we got off the bus she speed walks home. DO YOU THINK SHE DELETED THEM OR DO I HAVE THE G1 VIRUS?