Should I or should I not?

So I haven’t had the best connection with my sister in laws, they are always about themselves. Well my husbands sister is getting married next month and her bridal shower is this coming weekend. Now when we got married last year, the only thing she showed up for was our wedding and didn’t even talk to us and it has been that way probably since before we got married last year. So I’m asking for advice if I should show up or not? Her bridesmaids didn’t include me in any of the information for the shower so I would basically be going in blind and alone. We have been having nothing but problems with his family over and over again, I just don’t want to be apart of it. My husband is so over all the bs that he’s just telling me to not even bother showing up. So it would it be petty of me to just say screw it? I would give you the background about his family but that would be very long. Is anyone having similar problems with the in law family? Thanks for any advice.