I want your oppinions about an in-law situation..?

I moved to my hubby's city after marriage, whereby I really met my in-laws and my hubby's friends for the first time. I was feeling lonely bcoz my ONLY bro-in-law has a g/friend who rarely comes to visit us at home when she knew I'm needy of the company. We are both young women who could share many things together. My bro-in-law always visit alone, whenever Missy indulges with her own female friends. When my bro-in-law invited us over, it's 4 the same reason.I'm disappointed that I hve 2 stick with the guys. I wanted to know more.But when our parents in-laws hold reunions she''s always there 2 grin & bear. I felt bitter, bcoz i felt I'm not worthy of her company. She found out that I was BFF with another in-law, and NOW she wants me to include her in our outings.! What about my feelings when she left me out ? I'm thinking that 3's a crowd. The other in-law is the only 1, I can pour my heart out with, and I couldn't talk openly if others are around. Is this possesiveness or vengeence?