Cinderella not Invited to the Bridal Shower

I have two sisters and a mother. One of my sisters and my mother are hosting a bridal shower for my cousin who is my mother's sister's daughter. I did not get invited to the bridal shower. However, the bride to be invited my younger sister. The reasons for a 'no' invite told to me were; I was never closed to the bride to be, large gap in age difference and didn't want me to feel obligated to send a gift. I know the majority of ladies attending the shower simply because they are related to me. The funny thing is the majority of the invitees have little contact to no contact with the bride to be. Also , I personally have never had an issue or problem with my cousin or her mother. As a child I was very close to my aunt, spent the night at her house, vacations together.. I actually thought they liked me.. I guess not.. My question is: was it rude for the bride to be to exclude me since it is my sister and mother hosting the event? I certainly don't harbor any ill feelings. I'll send a gift for sure. But I'll stay home and sweep the house.