What's the deal with Helen on Lost?

I'm re-watching Lost for the first time on Netflix, and on the first season episode "Walkabout" Locke is talking to Helen on the phone right before he goes to Australia. From the conversation you get the impression that she is a phone sex employee. Did they just disregard this later or is there some explanation because isn't Helen the woman he had an on-off relationship with for years before he went to Australia?