Complex sentence: Many in her family thought that moving to Lansing was just an attempt by Post to forget her former boyfriend, and those who thought that way were probably right: while at Lansing, she began to investigate about her former boyfriend's supposed affair.
Split into simpler sentences: Many in her family thought that moving to Lansing was just an attempt by Post to forget her former boyfriend, and were probably right. While at Lansing, she began to investigate her former boyfriend's supposed affair.