Complex sentence: In 1979, Vonnegut wedded Jill Krementz, a photographer whom he met while she was working on a series about writers in the early 1970s, with whom he adopted a daughter, Lily, when the baby was three-days old.
Split into simpler sentences: In 1979, Vonnegut married Jill Krementz, a photographer whom he met while she was working on a series about writers in the early 1970s. With Jill, he adopted a daughter, Lily, when the baby was three days old.