baby shower and hurt feelings

So my husbands family and I are very close, closer than my own family. My SIL and her husband moved to Boston for a 5 year plan and that plan should have been up this year but they are kind of stalling. long story short...we are pregnant with the first grandchild and baby in more than 18 years. (husbands cousin was the last baby and he's a senior in HS). Her husband and her never want children but they love their nieces and nephews on her in laws side. anyways...she flew out for both of her SILs births (Boston to Portland Oregon and Boston to Alaska) and has now flown out for one day (Boston to Seattle) to attend an old coworkers baby shower. well...she said she won't be flying out for my one and only shower (she missed my bridal shower and all wedding events except for the ceremony since she was a bridesmaid) or the birth. She said they might come out a few months later for her company bbq and we can get together. now we all get along great and have fun together so it's just kind of weird that this is even an issue.