Q: Can I still co-sleep if I go to bed later than my baby?
A: You can, as long as you do it in a way that keeps your baby safe. The biggest hurdle is that you can't leave your baby alone in your bed (she might fall out). I'd recommend using a co-sleeper device that attaches to your bed (it's kind of like a play yard-meets-bassinet). With this, you can put your baby down and leave her safely unattended until you're ready to join her. Plus, since these devices have their own separate mattresses, there's no risk of you rolling over onto your baby or her suffocating from pillows or blankets on your bed.
Many parents are also concerned that the noise they make when coming to bed will wake their sleeping babies, but this isn't really a big deal. In fact, many babies snooze more soundly when there's a little background noise, since it makes them feel secure (they're used to all the sounds from being inside your belly during pregnancy). This doesn't mean you can have the television blasting at all hours, but you might want to leave the door open and expose her to the ambient noise of your home or even use a white noise machine so that your coming to bed won't be jarring to her.
When deciding whether or not to co-sleep, bear in mind that the American Academy of Pediatrics advises against it (especially for infants under 1) due to the risks of suffocation, strangulation, and parent rollover. However, if you do plan to co-sleep with your child, it is critical to take the necessary precautions to ensure his or her safety. These include making sure the baby can't roll out of bed, and that you're on a firm sleeping surface (not a waterbed or a featherbed). Young infants will be safest between the mother and the bed rail, not between two parents. And never sleep with your baby if you are under the influence of drugs, alcohol, or prescription medication that can make you unusually groggy.