I think it's probably coz she's not close to you. So naturally she just tag her Bro knowing that the Info will likely be shared to you too. Some people don't like to be tagged on fb. Due to "privacy" , "low profile" or what not. Perhaps she is afraid u would be unhappy if she tagged you all the time or on things u dislike. We all hv friends like that I'm sure. Just express to her your interest in the posts she share to your hubb when u all meet ? Probably she will include u too next time ;)
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