It took Alynn two days to escape the villagers, her would-be killers. Two days - the same amount of food she'd taken in her rush to escape.
Being magical was all very well, but its reliance on her eating was sometimes annoying. Getting food might not be a problem, but if she couldn't find enough she wouldn't have as much energy the next day - then even less after that.
Now, stuck in the Chiral Forest five days away from the nearest friendly town, Alynn felt doom impending: how could she keep going?
Alynn's back! Last week I asked about the scientific principles behind her magic. The answers there confirmed the viability of what I'd come up with. Alynn has magical energy, which she can use, converting with 100% efficiency, on any task she can think of.
The amount of energy is dictated by how much she eats: she gets half a Calorie's worth of magical energy (2000J) for every Calorie she eats. This means, on a normal day, she'd end up with about 4MJ of energy.
Now, she's stuck. Five days away from her target, where she'll try to start her life again, she's out of food and water, and has no shelter. And no experience with this sort of thing: while she can kill animals easily, they run away because they hear her coming; and she couldn't tell the difference between a sloe berry and a deadly nightshade berry.
How can she keep herself walking? This is the first day, so you have 4MJ to spend on getting her enough food, water, and shelter to get to the next day. After that, she'll have the energy you gave her in that consumption.
Her energy can be used for pretty much anything - apart from creating matter. She can synthesise things apparently out of thin air by finding the correct molecules (yes, her brain can do this) and reacting them to form the correct compounds, but only if she can make the correct conditions for the reaction. She cannot create new atoms or molecules.
Also note, if she creates an exothermic reaction, she won't absorb any energy from it (or any other energy source for that matter).