Daughter of Witches by Patricia C. Wrede is $1.99 from Open Road and is also couponable at kobo.
It is part of her Lyra Series
https://store.kobobooks.com/en-US/eb...ter-of-witches
http://www.amazon.com/Daughter-Witch...dp/B006BPL2XM/
In the oppressive city of Drinn, a trio of magical strangers offers a servant girl the chance of a new life
Drinn is not a safe place to be a witch. Ranira knows that better than most, for when she was just a child, the temple guards burned her parents at the stake for practicing magic. Now an indentured servant for a brutal innkeeper, she lives every day with the shame of her parents’ alleged crime.
There is no worse time to visit Drinn than during the Midwinter Festival, when the city gates are sealed so that no outsider can witness the temple’s secret rituals. And at Ranira’s inn, three guests have overstayed their welcome. Attempting to protect Ranira from her master’s cruelty, the three reveal their magical powers and attract the attention of the temple guards. Now, to save her new friends from certain death, Ranira must unleash the power that cost her parents their lives.