Our approach is to allow the kids to self wean themselves from our bed when they are ready. When they are interested we get them their own single bed and the ages they have slept there full time have varied (ds1 was 4yo, dd2 is 6 and still sleeps with us often and dd2 is just 3yo and is starting in her own bed every night but doesn't stay there for long). The key is to have plenty of space for everybody to be comfortable and separate bedding for older kids. We have atm a King sized bed with a single pushed up for dh, myself, dd1 6.5yo and dd2 3yo although dh often sleeps in another room because he snores and this is also the room where dh and I meet up for romance...