Our oldest is 5 and we still welcome her into our bed. Our 19 month old still co-sleeps. We transitioned our first out at 22 months when I stopped nursing. It took another 6 months to get her used to the idea and I would sometimes sleep with her in her room.
People always know someone who has a kid that's older...yadda yadda! I love having them close because they don't stay little forever!