What does "send her/his fleeing for" mean?

Question

I've come across with the sentence below:

Hitler's dream of empire had yet to crumble and send her fleeing for the shadows

.

I searched in online dictionaries but I didn't find any explanation for it.

So, could you tell me please what it means?

The fuller text is:

She fired six times shots on the shore of the Lake Rusalka, not attempting to hide what she did. Why would she? Hitler's dream of empire had yet to crumble and send her fleeing for the shadows... They called her... The Huntress. She was the young mistress of an SS officer in German-occupied Poland.

The Huntress by Kate Quinn

Answer 1

If I send you fleeing I do something that causes you to flee.

The cartel moved into the city and sent the local drug kingpins fleeing.

In your example, the syntax is like this:

... had yet to ... send her fleeing

That is, "had yet to" governs crumble and send.

The driver of the car had yet to commit an infraction and give the police officer probable cause to stop and search the car.

The syntax is somewhat elliptical:

The driver of the car had yet to commit an infraction and [thereby] give the police officer probable cause to stop and search the car.

The dream of empire had not crumbled yet [which it would eventually do] and sent her fleeing.

We can avoid the ellipsis by saying it so:

Hitler's dream of empire had not yet crumbled to send her fleeing for the shadows...

The cartel had not yet arrived in the city to send the local drug kingpins fleeing.

The infinitive clause complement in that pattern is a result not an intention or purpose.

Answer 2

We can use the verb 'send' with an object and a word or phrase:

I sent her away.
I sent him to London.
The weather sent me into the house.
I sent the stone flying through the window.

The crumbling of Hitler's empire sent her fleeing (running away from danger) into the shadows (to a hiding place or series of them).

Send

Flee