Sound like she's doing what she said she'd do.
Don't be overly impressed by the bells and whistles--a video tour, for instance. Talk to her about it; they don't cost that much.
But: 2 open houses and 20 showings isn't bad. Not at all. The fact that you've only had one offer, one you consider low, suggests to me that you're overpriced. Yes, I know you said you weren't overpriced. I'm fully aware of that. But you've had 20 people who wanted to see your home. Nineteen decided not to make an offer and the twentieth made an offer, but one you consider low.
The other possibility is that there's something about the house or the neighborhood that's turning off potential buyers. Again, I read your comment that it's a newer house in excellent, presentable condition. And maybe it is. But maybe it's not.
Why not post a link to the listing? That might allow some of us to take a look and give you suggestions.
Hope that helps.