This Isabel person needs to be told that they are not a senior person and whether they are or not any task requested of them is not beneath them. If they are asked to do something unless they are incapable of it for some reason they need to step up because it's needed not because it's good or bad for somebody's career. They should be made to understand that these smaller items are not given primarily to one person but are spread fairly evenly to everyone. She has no special right over her colleagues to only have high value work and to only have influential work. Maybe they've been treated as if they are top-tier their entire life and that's what you're seeing with the car, but it really doesn't matter why. What matters is that they understand what their job is and that it includes some lower value tasks in addition to the higher value.