This is an interesting take, but isn't she free to leave anytime she wants? Also, practical seems more like an internal trait than an external one, and don't the other character bear most of the conflict that comes from her practicality?
I don't think it is ignored. It's not specifically brought up in each act that she needs money, but each act does show us the conflict that comes about because of that. If I were to describe her throughline in one sentence, it would be something like "When Travers runs out of money, she must consider selling the movie rights to Mary Poppins." And isn't pretty much everything after that opening scene in relation to her considering whether to sale the rights? Then at the end, we see that she has the money to rehire her housekeeper and is writing again.
Not sure if you've seen it, but compare that to something like Frank Hamer in NETFLIX's The Highwaymen. One of the first things we see Frank do in that movie is try unsuccessfully to shoot the way he used to because he's rusty and old, which seemed to be setting up a nice MC throughline about dealing with a frail and aging body. After that, we see him run out of breath once and talk about the number of bullets he has in him, and that's about it. Little to no conflict that can be traced back to that set up, and no payoff at the end where he figures out how to deal with being old and rusty. That's a problem that got ignored.
What do you think @RailwayAdventurer?