I started co-sleeping with my DD when she was 10 months old. Previous to that she had been very strictly in her own cot (something which i now regret). At 10 months she went to bed in her cot and then her first wake up of the night would bring into our bed. It was fantastic got proper sleep for a change, and was even easy to wean her from night feeding. She is just over 2 now and sleeps in a big bed in her own room. Some nights she gets up in the middle of the night and crawls into our bed, other nights she sleeps through. Obviously everyones experiences are different, but co-sleeping, starting late for us worked for our whole family.
Good luck with your sleeping arrangements.