It's wrong to hold someone's past against them.
Jill has recently lost a treasured necklace and is a long-time friend of Sally, who stole a lot as a teen, but has since reformed.
Jill wants to find out what happened to her necklace.
Jill realizes that Sally is not a thief anymore and asks Sally if she could help find the necklace.
Knowing Sandy's past, Jill immediately suspects that Sandy took the necklace.
Sandy and Jill work together and become closer as friends.
Sandy resents Jill for the accusation, and the two never speak again.