An American woman who converted to Islam and joined the Islamic State in Syria, leading an all-female military battalion, was sentenced to 20 years in prison by a US court Tuesday. Allison Fluke-Ekren, 42, who grew up as a Christian on a farm in Kansas and converted to Islam as an adult, was sentenced in federal court in Alexandria, Virginia, after pleading guilty to providing material support to a terrorist organization. Prosecutors told the court that for more than eight years, Fluke-Ekren “committed terrorist acts on behalf of three foreign terrorist organizations across war zones in Libya,…