I didn't think any of Kathy Cody's roles were so bad either. At the time I was around the same age and knew girls a lot like Hallie and Carrie, confronted with many new options for their futures while dealing with age-old adolescent concerns. At least Hallie seemed to have some normal aspirations for young teen girls in 1970--- at one point [spoiler]she expressed a desire to live on her own and a job when she grew up,[/spoiler]while skittishly interacting with a young teenaged boy (well, this last I surely COULD identify with.)
Unfortunately, as almost everyone has observed, the way the character was written gave way to incompetent whining and weeping like a much younger girl--- channeling Denise Nickerson's characters?--- not to mention they dressed the pretty, budding young actress like a 10-year-old in the 1970 segments, including KNEESOCKS. (Actually her 1840 costumes were much more accurate for a girl that age.) Contrast this with KC's guest shot on "Gunsmoke" several years later, as a more complex sort of victim.
However, one COULD choose to see the Hallie character as the product of a sheltered upbringing, typical of an only child of perhaps older parents, which may have included private or parochial school--- as I did, having, myself, been made to suffer through kneesocks and ugly unforms as a student at Saint (insert martyr name here)--- coupled with the loss of those parents. Thus the dress and behavior MIGHT be explained by the girl's lack of worldly sophistication despite her aspirations, magnified by her immurement in an environment NOT designed to help her mature (in short, her apparent fate to become a typical DS ingenue.)
Another problem with KC's characters, I suspect, had to do with the skittishness of the writers, perhaps in regards to censorship issues--- has anyone ever ASKED them? The original "Turn of the Screw" story upon which both the 1897 and 1840 stories were initially based, implied to many (however intended by Henry James) that the very young children in the novella were alleged victims of some form of sexual abuse by the servants. One could get away with the implication (as long as it was not explicit) in films back then, but on TV in those days--- no way, and certainly not on a daytime show largely watched by minors.
So in 1897, the TOTS plotline, involving very young kids, shifted focus from those kids (except for "acceptable" plotlines like [spoiler]immolation by a parent, black magic, murder by a ghost, and posession!!)[/spoiler] , and by the 1840 plotline, dealing with attractive adolescents, the problem was magnified. One wonders whether it was a relief when David Henesy, [spoiler]due to family reasons, soon vanished from the show, and instead of expanding on young Carrie's relationship with him, or her seeming interest in older men (including Gerard), they could bring in a slightly older but "normal" boy to be her serious love interest,[/spoiler]thus throwing off the necessity of explaining exactly WHAT hideous activity was supposed to have happened to [spoiler]knock off both kids and most of the adults[/spoiler] in 1840 and 1970.
I think this was a burgeoning dilemma on most soap operas in the late 1960s and early 1970s, as they strove to accommodate modern issues and increasingly complex adolescent problems in their storylines, while performing a balancing act with censorship and sponsors. In the early 1970s, for example, on "The Doctors" there was a whole storyline about one Doctor's young teenaged daughter who had run away from home and soon found herself the target of a predatory older man. They cast a very slight and girlish-looking actress, who was actually in her early 20's at the time. The actress was Julia Duffy, who later went on to marry DS's "Trask", Jerry Lacy. Luckily, the character was rescued with her virtue intact, but in the build-up, had to play some fairly mature scenes which used to be considered very unsuitable for younger actors.