Like Rodman, Shelly Rasmussen represents all of the things that Lyman Ward hates about 1970s hippie culture. Unlike Rodman, however, Shelly also happens to be an attractive lady, which throws good old Lyman for a loop—and then some.
Although Lyman never wanted to hire Shelly in the first place, she proves to be an invaluable assistant. She works hard. She's good with details. And—most importantly—she's genuinely interested in his grandparents' story, even if she seems a bit overly interested in Lyman's stake in the whole deal. That's actually Lyman's biggest gripe with Shelly: her obsessive need to figure out why he's "spending all this effort trying to understand [his] grandparents' lives" (7.7.46).
Don't get it twisted, though: Lyman has tons of beefs with Shelly. Most of these center around her unconventional lifestyle choices: her tie-dyed attitude, for example, which was surely fostered by her estranged hippie husband. In fact, it's Shelly's relationship with her husband that forces her to make the biggest decision of her young life: whether to get back together with him and move to his commune, or kiss her marriage goodbye and go back to school.
Tellingly, Shelly goes to Lyman for advice. She even shows him the brochure for her husband's commune, which Lyman (predictably) disses for its "softheadedness" and utter ignorance of "both history and human nature" (8.6.66). This reveals that Shelly respects Lyman's wisdom, even more than her parents', to an extent. In a similar way, it also shows how much Lyman cares about Shelly: after all, in his dream, she chooses to go to college instead of the commune.
It's not surprising, really. Lyman is spending most of his free time writing about a woman who possibly made the wrong choice of husband. Why wouldn't Lyman want to save Shelly from making the same mistake?
In the end, Lyman realizes that he just wants what's best for Shelly. Sure, her passionate feminism sometimes gets on his nerves. And, yeah, her alluring femininity gets him a little too revved up at other times. But the truth is that Shelly is a uniquely intelligent, driven, and empathetic woman, and she deserves respect for it. You know, we might even say that she reminds us of a certain grandmother...