Complex sentence: Now in her late thirties, she has finally decided to have a child on her own, but her plans change when she discovers she has only the slimmest chance of becoming pregnant because she finds out her uterus is T-shaped.
Split into simpler sentences: Now in her late thirties, she has finally decided to have a child on her own. Her plans change when she discovers she has only the slimmest chance of becoming pregnant because she finds out her uterus is T-shaped.