Tanya speeds up her thoughts as much as she can and tries to think this through without visibly taking a minute to deliberate.
If they want to capture or to kill her, an ambush in a prepared position in close quarters is their best bet. They might have realized they can't take her head-on at the gate and asked her to come inside for that reason. They could also drug or poison her food.
But she has to talk to some locals and get their help. And the quicker the better; she is well-trained in wilderness survival, but hunting and preparing alien animals is an unappetizing prospect.
What has she learned so far? That they are telepathic, which is excellent for her prospects. That this telepathy is magical in nature (well, it would have to be), which implies they might have other magical abilities; this potentially increases the risks they pose to her and, again potentially, reduces her bargaining value.
The soldiers called an officer; they couldn't hail her telepathically themselves. So not everyone is able or trained to do this. This is magic used strategically, a resource allocated by this army, not a native ability of all orks. This organization speaks well of them.
A rational organization would not attack an unknown neutral party who might become an ally. But it might try to capture or coerce her to get a better bargain, if it did not expect reputational losses from doing so. Reputational losses which are very unlikely, since she has admitted no-one knows she is here.
If she refuses their offer, her best alternative is to find a smaller, weaker group of people (which would still have to include a telepath mage). Essentially, to do to them what she fears they might do to her, to coerce them where she has the upper hand.
That is not a viable long-term solution; she can't live off enemy land (or its farmers) forever, and moreover she doesn't want to, she'd rather work with people than against them. In every negotiation, agreements necessarily conform to the relative power of the parties; even if she is free to leave she doesn't have anywhere to leave to.
They are fighting a war, which implies an enemy, and likely one or more neutral parties besides. Ideally, she would learn about all of them before picking one. The locals will naturally try to make her commit before she learns anything, and to make it costly for her to change sides later.
If she flies away and finds the other side of this war, she will be in the same position except for having burned her bridges with this group. There is no prior reason to think another side would be better for her.
However, it is likely there are more than two groups, and it is likely that the first one she encounters is not the best one. A group which is not at war would be less incentivized to turn her to their use.
This is like the secretary problem, except she doesn't know how many groups there are and she can't perfectly evaluate this one before rejecting it. However, it is very likely there are at least three large organizations in this world and so she should reject at least the first group she meets, while trying to learn as much as she can.
She will try to learn more, but be ready to bolt at the first sign of danger.