Master of Iron

In Master of Iron, the conclusion to Tricia Levenseller's exciting and romantic Bladesmith duology, a magically gifted blacksmith with social anxiety must race against the clock to save her beloved sister and stop a devastating war.
Eighteen-year-old Ziva may have defeated a deadly warlord, but the price was almost too much. Ziva is forced into a breakneck race to a nearby city with the handsome mercenary, Kellyn, and the young scholar, Petrik, to find a powerful magical healer who can save her sister's life.
When the events that follow lead to Ziva and Kellyn's capture by an ambitious prince, Ziva is forced into the very situation she's been dreading: magicking dangerous weapons meant for world domination.
The forge has always been Ziva's safe space, a place to avoid society and the anxiety it causes her, but now it is her prison, and she's not sure