The use of a pacifier has been linked to lowering the risk of SIDS. It is not exactly known why, but it could be that the pacifier might provide a tentlike effect between it and the bed. This could help in the event the baby's face becomes smothered into the mattress and/or loose bedding by providing a breathing 'hole'.
Although pacifiers shouldn't be used before 1 month of age because they may interfere with breastfeeding, they are perfectly fine to use after that. Don't force a binky if the baby doesn't want it, but if she takes to it, by all means let her have away at it.
So, not only are pacifiers ok to use, but they may help reduce the risk of SIDS. The cons against pacifiers are so minor and many not even be substantiated, but the link to reduced SIDS ocurrances has been evidenced by multiple studies in many different countries.