Sheba was kind of a bully.

Very bossy. Didn't exacly "play well with others." That's one thing I loved about her, but I'm not sure the other two miss her all that much. Even the day before she died, Sheba jumped up on the bed and smacked Gracie in the head to chase her off. Gracie weighed close to three times as much as Sheba, but the old gal was still the boss.
Gypsy seemed a little mopey for a while after Sheba died. She was always weirdly protective of Sheba, even though they were never buddies. If I had to clip Sheba's nails or give her medication that made her complain, Gypsy would run up and bite my leg. Then again, that could be, "I don't know what you're doing to her, but I'm not going to be next!"
I do miss her a lot, but as I've said elsewhere, grieving for Sheba is a lot easier than the worry and helplessness I felt when she was sick. There were a lot of touch and go moments during the final six weeks when her heart problems were first diagnosed. She'd be stable and doing great, then go downhill and scare the poop out of me until her meds were adjusted, then she'd do great again. All in all, I'd say she had 18 great years and maybe, if you added up all her bad days over her lifetime, the equivalent of two or three bad weeks.