The Queen's Vow by C.W. Gortner Review-Post
This is a fascinating story of Isabella, who at a very young age was taken from her mother's home to live with their half- brother King Enrique, so he could have them under his watchful eye. At the age of seventeen she finds herself heiress of Castile, the largest kingdom in Sppain. She marries the man she loves although forbidden to her, Prince of Aragan, Fernando and they unite their two realms under one crown.
After many pregnancies to produce a male heir, she has only one son and the rest are daughters. She also endures many years of conflict and wars to get to her goal.