Fantasy - Woman gets transported to a different place and gathers companions for a mission

[Katherina]

Not Outlander. I picked up a book at random in my middle school library around 2010, even then the book had some miles on it. It's a woman who gets transported to a different place and time. She gathers a team of companions belonging to different ethnicities and tribes. One of which is a swordswoman who (view spoiler)[ has to fight her mentor to the death (hide spoiler)] another is a woman from a tribe of people known for having no feelings who (view spoiler)[ ends up crying. Heroine gets commended for making the apathetic woman have feelings (hide spoiler)] Feel free to throw names out there - again book had some miles in 2010 so any suggestions welcome!