He's trying to kill us--could ruin him--worry about that later--grab your sister and go.
Great. Great. What now? If she had landed somewhere habitable she could just sit tight until someone found her--they'd look, she knows she would. But--well. She's a mage. She's not going to die in the desert. But it's not likely to be pleasant. "Illia," she says tentatively, pointing to herself.
And then she bolts, because whatever just happened probably means she's not welcome anymore. She dashes to the oasis, drinks as much water as she can hold, fashions a makeshift waterskin out of her skirt and magic, fills it, and runs off in a random direction as fast as she can sustain herself.
Well, she was doing alright before she did magic. She memorizes its location, lets her vision go back to normal, and heads in that direction. When she gets within normal vision distance of it, she slows to a normal run, and then a walk. She drinks from her impromptu waterskin, then lets her skirt assume its normal properties and shoos the remaining moisture from it.
The lion people imagine that a sufficiently fancy ehis could make a city fly, that's not the problem, and it is not so impossible that there could be kinds of magic they don't know about because the kyis don't do them and they don't talk to people far away very much; the problem is that they are really sure that all these kinds of magic exist and she hasn't heard of any of them.