Shady friend?? Or am I over-reacting??

Ok.. so I’ve had a close friend for about six years. I would put her in my top 2 or 3 for best friends.

I also started dating my boyfriend about 3 years ago and of course introduced them. We all would hang out often and everything was great.

Lately, things have gotten a little strange. Whenever we would have plans that this friend was coming to she would text HIM instead of me for details. She would also start texting him at random times to ask random questions as well as emailing him online. She was never saying anything inappropriate, she just seems to be replacing the friendship she had with me, with him.

His birthday was in April and this friend made him home made brownies and a card and brought it over.

My birthday was in June and I got a happy birthday text and she didnt even bother to come out with the rest of my friends.

Do I have a right to be upset about this? At this point I just pretty much want to cut her out of my life. She has always had the reputation of being promiscuous and would brag about landed guys with girlfriends. I wouldnt think she would set her sights on my boyfriend but it appears she somewhat has.