Requite Series by Ankaret Wells

Tzenni Boccamera wasn't a soldier or a diplomat. She was an engineer. But when Tzenni's sister Catha was captured by soldiers from a rival Spire, there was no one else to go to Catha's rescue. Tzenni didn't expect the rescue to involve a sarcastic bodyguard, a plot to bring down the Spire, or an alien species. And she certainly hadn't meant to fall in love...

In this sequel to The Maker's Mask, Tzenni Boccamera has solved the mystery of her missing sister Catha, but there are more troubles for her to overcome.The Hawkwood brothers want salvage rights to a fallen Spire. Ligeia Boccamera wants to rescue her sisters. Facade Blue wants to see the culmination of a plan four hundred years in the making, and no one has any idea what the alien grues want, or even how to talk to them. No one but Tzenni Boccamera.. moreIn this sequel to The Maker's Mask, Tzenni Boccamera has solved the mystery of her missing sister Catha, but there are more troubles for her to overcome.The Hawkwood brothers want salvage rights to a fallen Spire. Ligeia Boccamera wants to rescue her sisters. Facade Blue wants to see the culmination of a plan four hundred years in the making, and no one has any idea what the alien grues want, or even how to talk to them. No one but Tzenni Boccamera... 'Fantastic conclusion to the story which began in The Maker's Mask. The action ramps up with the intrigue moving onto a bigger political stage. [...] Highly recommended for the brilliant world-building, twisty plot, witty dialogue, and characters that you can't help falling in love with!' less