Sister-in-law Rant - kinda long

mother nature • new mama, wife and dog mom. the stork dropped colin john off on oct 12 and were spending time trying to figure him out!
My husband's sister and I usually get along great. My husband and I dated for a good 8 years or so before we got married, so his sister and I became pretty close. She's about 6 years older than me and has three kids, 11 boy, 10 girl, and 7 boy.
My husband and I chose not to find out the baby's gender. We both wanted to keep that excitement for the birth of the baby. Of course, people are always guessing at what we're having. Most guesses have been boy. 
My sister in law text often, but she texted me randomly one day. The text said "I'm a little bit sad that you're having a boy. Don't get me wrong, I love babies, and still am totally excited, but I was hoping for a girl for my daughter to hang with"  
I responded, why do you think we're having a boy?! And, that we'll find out in a couple months (it was August when she texted me this). She said, I just have a feeling. 
Ok, this bothered me. I don't understand why she would say that, but I let it go and forgot about it. 
Flash forward to this past weekend at the baby shower my husbands family had for me. She made the same comment again, this time in front of all her aunts and while I was opening gifts. I really wanted to say something to her, but didn't want to make a scene in front of family. 
I'm bothered by this again. Maybe it's pregnancy hormones, but I don't know why she would feel it's okay to express HER gender disappointment with ME about OUR baby?! I'm trying to tell my self that this issue is about her and has nothing to do with me, but I'm having a hard time wrapping my head around it. 
Any thoughts???