Change the comma after concerned to a period.
She was growing concerned. The same battered old pickup truck had driven by the place three times now.
Pick-up and pickup are both correct, although the unhyphenated form seems more common now.
I think growing concerned is somewhat bland, and it lacks concrete detail, but that doesn’t make it “bad writing.” If the important thing in this scene is whatever’s going on with the truck, rather than the POV character’s emotional reaction to seeing it, you don’t want to bog the scene down with a lot of description about how this character keeps sneaking glances at the road, dreading the truck’s return, her face twisted in rising panic… You put the details where you want the focus, and keep the rest a bit indistinct.