Here's what I do with my character when role playing:
She has pretty good control over her transformations, she's had the disease for a few years. She acquired the disease through the Companions.
She completed The Ring of Hircine quest, so this gives her a bit of control over her mind when she is transformed, so she can tell herself which creatures are okay to kill (usually. If she does somehow lose control, or if the ring is taken from her, then there is no way she can tell herself how to behave while she is an animal).
She refers to younger people as whelps, just as the rest of the Companions did.
However, the Ring has made her beast form a bit more savage, and made her willing to feed on less desirable corpses, such as vampires (although she thinks they are repulsive). It heals her very little, if at all, and she feels sick afterward.
Since she has a bit of control of her beast form, her thoughts in human form are a bit animistic. To her, everything is a Hunt. The Hunting never stops. And every once in a while, Hircine will speak to her. She has no choice but to obey his commands.
She can't sleep, and when she does, she has nightmares. Sometimes she transforms in her sleep.
She does crave hunting in her beast form, and doesn't usually fight it.