When a mysterious stranger thwarts a sophisticated attempt on her life, an isolated mathematical genius must leave behind everything she knows to flee cross-country with her new-found protector in search of clues to the motives and identities of her would-be assassins.

It's not so much the motivations of the 'would be assassin' or the identity that should be her goal, rather her end game is to catch the person so they don't try it again. This should be specifically described in the logline as her goal.

On a separate note, a little pet peeve of mine (other's opinions may vary) is the use of too many adjectives in a logline.

The goal of a logline is to present story elements that on their own mean little but when combined together mean a lot. A naive farm boy who wants to defeat a galactic empire works so well because the odds are stacked so heavily against the MC. There was no need to describe the MC as helpless, poor, or under-resourced and the empire as known for its merciless nature:
After the evil galactic empire kills his family, a naive farm boy must learn to become a Jedi night in order to defeat their army and free the galaxy.

Now with too many adjectives:
After the notorious evil galactic empire kills his loving adopted parents, a poor and naive farm boy must become one of the mysterious Jedi nights in order to defeat their army and free the enslaved galaxy.

You'll do far better expressing a lot of story information with fewer adjectives than with more.

Here is your logline stripped of redundant adjectives and descriptions:
After an attempt on her life, a misanthrope mathematician must team up with her savior to catch the would-be assassin.

"When a mysterious stranger thwarts a sophisticated attempt on her life, an isolated mathematical genius must leave behind everything she knows to flee cross-country with her new-found protector in search of clues to the motives and identities of her would-be assassins." (41 words)

So what exactly is her goal? What does she intend to do once she's discovered the identities and motives of these assassins?

I think you add a little too much description. Here's an example, just cutting out some of the unnecessary words.

After an attempt on her life is thwarted, an isolated mathematical genius must flee cross-country with her new companion to investigate the people trying to kill her. (27)

I have a few questions that don't need to be answered in the logline, but I'm asking you because you should know. What is the motivation of the mysterious stranger? Why is he/she helping her?
Also, what is the motivation of the antagonists? Why do they want her dead?

Something I do for my stories is to create a logline from the antagonist's perspective, to flesh out their motivation. I also do it for any of the major supporting characters in the story.

The biggest problem I see is that your logline doesn't present and show off a hook. What makes this story special, unique? If a producer were presented with two loglines for thriller concepts, what would make them want to read your script over the other? Find the hook, the something interesting and put it front and center in the logline. So it can hook the reader.

I hope this helps.