My two, almost three year old daughter still wakes up at night. normally starts to cry until she's in my bed with a sippy. i don't want to let her cry?

Why: Infants & toddlers can learn the important skills of self settling & self sleeping if allowed during the first weeks after birth.It may become hard when they enter the separation anxiety stage if they haven't been allowed to gain the skill. You may benefit from ferbers book "solve your child's sleep problem". By three she knows she needs sleep, but you are fostering her continued dependence.