Family member issues

My husband has a cousin that absolutely disturbs me to no end. First of all, yes she is his cousin and not a "cousin". She claims that her and my husband are super close. They talk about everything and he is her go to person when she needs advice. She would constantly post on his wall when he was deployed about how much she "missed his funny face" and how she couldn't wait to hug him when he got home. Deployments are not easy for our family and it really put a strain on our marriage. She would make sure that he knew, on his Facebook wall for everyone to see, that she loved him and would always be there for him. If I made a nice post about him or wished him a happy birthday or something nice, she would immediately post after me and then make a comment to my husband on my post. The husband and I had a discussion about this and how I didn't approve of her overzealous ways of showing love for her cousin. It seemed weird to me especially since she had never done it while he was at home. Needless to say I got a nasty little message from her stating that I was basically the daughter of Satan. Since then she hasn't said anything to him via Facebook. No wall comments, no likes on his pictures of our family, nothing...until today. Shortly after we announced our pregnancy on Facebook, here she comes with her "It seems like forever since I seen you!" And posting a picture of her and my husband from her "on this day" thing. This same cousin has also used pictures of herself and my husband multiple times as her profile picture. Am I losing my mind or is she crossing a line here? She's not as close to him as she would like to claim since she has made no attempt to talk to myself or our daughters. Her focus has always been on my husband and him alone.