Ask Texas – My Sister In Law Brings Over Her Own Food We We Invite Them Over To Eat!

Buzz Question- SO this has been bothering me but not sure how to handle it. Every time I invite my Sister In Law and family over to eat, SHE BRINGS HER OWN FOOD! At first, I was surprised but it has happened several times. I asked her if she was on a special diet or something and she told me 'NO'. Um, I dropped it but she will still do it. I asked my husband about his sister and he just says she's like that. UM, is my food no good enough for her?  What's happening here?