I agree completely with him saying that FGM is a problem that is rampant within the Muslim community on a global scale, but he's being completely disingenuous to say that it's a Muslim only issue which is what she is pointing out. FGM happens across cultures and religions and she is right in saying that this is not a practice that is born from Islam. You can go through a list of countries that perform FGM and see that while yes, Muslims in a lot of countries are the primary perpetrators of FGM, but there are also plenty of countries with high populations of Christians and other ethnic groups that do too. Notably:

Benin

• "FGM is prevalent in 49% of Muslim women, 15% of Protestants, 12% of traditional religions and 7% of Roman Catholic women."

Burkina Faso

• "FGM is prevalent in 82% of Muslim women, 73% of traditional religions, 69% of Roman Catholics and 65% of Protestants."

Central African Republic

• "FGM was prevalent in 46% of Animist women, 39% of Muslim, 36% of Protestants, and 35% of Catholic women."

Chad

• "FGM is prevalent in 61% of Muslim women, 31% of Catholics, 16% of Protestants, and 12% of traditional religions. The prevalence also varies with ethnic groups; the Arabs (95%), Hadjarai (94%), Ouadai (91%) and Fitri-batha (86%), and less than 2.5% among the Gorane, Tandjile and Mayo-Kebbi"

Eritria

• " FGM is prevalent in 99% of Muslim women, 89% of Catholics and 85% of Protestants."

Ethiopia

• "FGM is prevalent in 92% of Muslim women, 72% of Protestants, 67% of Catholics and 67% of Traditional Religions."

Guinea

• "FGM is prevalent in 99% of Muslim women, 94% of Catholics and Protestants, and 93% of Animist women."

Kenya

• "FGM is prevalent in 50% of Muslim women, 33% of Catholics, 30% of Protestant women."

Liberia

• "Based on this estimation method, the prevalence of FGM in Liberia has been estimated as 58%"

• Referring to religious composition, "According to the 2008 National Census, 85.5% of Liberia's population practices Christianity.[2] Muslims comprise 12.2% of the population, largely coming from the Mandingo and Vai ethnic groups.[2] The vast majority of Muslims are Malikite Sunni, with sizeable Shia and Ahmadiyya minorities.[3]"

Malawi

• FGM is practiced in a country that is primarily Christian