My mother in law is 77, she has been shoplifting, we have talked to her and she says she won't do it again. Yesterday we came home from the store and she had items in her purse that she didn't pay for. She is adamant that she paid for them. I have the receipt, she did not pay for them. I confronted her about one of the items, and she admitted she took it but not the other 2.
Option B depends on whether or not you are legally responsible, such as a POA or Guardian, who takes her shopping. In this case the court may find you negligent and order you make restitution to the complainant.
Option C is the simplest, just don't take her to stores, period.
Oh, I'm sorry. I'm so evil. The problems underlying shoplifting are often deep. For example, we had a commanding officer at Ft Benning whose wife was a chronic shoplifter. They could have easily afforded the things she took, but she took things, anyway. I am not a psychologist, so I don't understand the need and compulsion to steal. You may want to address that psychological problem or just leave her at home.
Or just do not take her shopping. If you do, you know you have to keep a close eye on her. Do not let her take the purse or anything else into the store where she can hide things.