J.C.
My girls are 5 years apart. (My son, who was in between my girls passed away when he was 17 days old.).
My girls could not be closer. My oldest is just so grateful to have her sister and spoils her more than I do😊 and my youngest could not help but love her big sister that is just so good to her. My youngest is really easy going. They both also share a love for the theatre and acting/singing and I think that keeps them close despite the age difference.