Transgalactic Antics by J.J. Green

Watch out! Carrie Hatchett has a plan.

Carrie's impulsive, reckless nature gets her in trouble again, and if she wants to keep her job as a Transgalactic Intercultural Community Crisis Liaison Officer, she has to pass remedial training. 

Little does she know that her survival and the future of the galactic empire are also at stake. 
With the help of her level-headed bestie, Dave, and her fellow alien trainees—an intelligent slug, a mysterious box, a large green blob, and a cylinder of hair—she might just succeed.

But so much stands in her way. A brain scan confirms that she isn't cut out for the job, and a blast from the past rears her beautiful head, sending Carrie into a crisis of self-doubt. 

When the evil mechanical aliens, the placktoids, return, Carrie must put together a plan that actually works. A plan to rid the galaxy of the placktoid menace, and save her life. 

Transgalactic Antics is book three in the light-hearted, fast-paced Carrie Hatchett, Space Adventurer series.