I am a firm believer that babies wake up & cry for a reason, that reason could be anything from uncomfortable, to having had a stressful day & leaving them to cry doesn't really help the problem.
Although you personally don't want to make a habit of being there until she falls asleep (I personally don't see it as an issue when my children from time to time need that), once they get to trust you are there for them, then gradually over a few days you try to leave earlier, always responding to their need.
I think if you respond as soon as she crys & leave as she settles she sees the "consistency" & will respond, it may take a while (hour or more isn't unreasonable) in the early days, but if you keep changing then she has no consistent method & it takes longer