I don't know what to do!?!?

[Lovey]

I've known my best friend Gracie since about 7th grade. I didn't really start to consider her to be my best friend until after freshman year (we're juniors now). She's said to me before that I'm very close to her in a different way than other people and we say I love you to one another a lot. I love her a lot, she's very close to me and she is very important and special to me as a friend.
There's another girl, Molly, who is apparently very good friends with Gracie as well, and does more things with her. They appear to be good friends and they've known each other a little longer than we have, but I always think that she's my best friend and not Molly's. I still get a TINY bit jealous of them together because Molly and the other girls in our inner group are always having surprise birthday parties and pre-dance parties and other get-togethers with people I'm friends with, and I'm never invited, which kind of doesn't really feel good because Molly is always putting pictures from the things they do (without me) on Facebook and flaunting it around whenever she's with Gracie, which kind of annoys me. I really want Gracie to know she's my best friend and be closer to me than with Molly. Is Molly trying to steal my best friend?? What can I do?!?!?!

[Masquerade]

Molly isn't trying to steal her away from you if she's known Gracie longer than you have. i understand the tiny bit of jealousy, but maybe you should make plans with Gracie and not include Molly.