Complex sentence: The nun had been admitted to the holy life as a toddler but the young woman was unsuited to the enforced celibacy of the life of a nun and became pregnant by a lay brother in the attached male community.
Split into simpler sentences: The nun had been admitted to the holy life as a toddler but the young woman was unsuited to the enforced celibacy of the life of a nun. She became pregnant by a lay brother in the attached male community.