She was originally a missing person. Ballard had a tape she made, presumably given by whoever filed the report. He apparently was investigating the Dollhouse, linked Caroline to it, and then developed a Prince Valiant type thing. re: Ballard I don't think it's just the "signing into slavery"...
It could be argued that's still merely Echo reacting in a manner as the rich lady would have. In this case the benefit is to Adele. It's not entirely clear if she believes it was a facsimile, or actually her friend; but obviously rich lady believed it was going to actually be herself, after her...
(If the ex-FBI guy did, of course.)
To be correct, it's code name November who had a daughter, though I didn't notice the name on the grave marker. And as for Caroline, not everyone in real life is "interesting" either.
"Immortality" may be part of some of the client's thinking, but having one's memories and personality played back in someone else's body... He/She may act and sound like you, but it's not you.
The FBI and the general public apparently believe that the Dollhouse is just an urban legend. But that begs the question, how do these rich people find the Dollhouse, or even know there is something to be looking for? Re: Cute neighbor chick - She offed the disgraced handler? I thought she...