One of my family members is known to take things, as a teenager, 7-16 yrs. She would take items of clothing. 17 to 19 yrs. She was stealing money & food from her convenience store job. Now she's 21 and moved out & has been moved out for these reasons since 18 yrs. Old She is now back in our lives & things have been disappearing , music cd's , a cookbook that was very important to me (given to me by her grandmother)& a baseball jersey ( given to me by her grandfather ) that also meant a lot to me . I am her stepmother. I just don't know how to handle this. I confronted her 1 time about the jersey & her father confronted her 1 time and she is mad at us because she claims she's tired of hearing about this jersey. I can't help but feel suspicious. I just asked her if she had seen it (as she was one of three other people in our house at the time it went missing) I am trying to understand however it is difficult. My questions are what are the symptoms/signs for me to look for besides the fact that things are missing.

Symptoms of kleptomania may include:

Powerful urges to steal items that you don't need
Feeling increased tension leading up to the theft
Feeling pleasure or gratification while stealing
Feeling terrible guilt or shame after the theft

Unlike typical shoplifters, people with kleptomania don't compulsively steal for personal gain. Nor do they steal as a way to exact revenge. They steal simply because of an inexplicable urge. Episodes of kleptomania seem to occur spontaneously, without planning. However, stressful events, such as an argument, may trigger an episode of kleptomania.

Most people with kleptomania steal from public places, such as stores and supermarkets. Some may steal from friends or acquaintances, such as at a party. Often, the stolen items have no value to the person with kleptomania. The stolen items are usually stashed away, never to be used. Items may also be donated, given away to family or friends, or even secretly returned to the place from which they were stolen.

Yes, the person who has kleptomania will be sorry for what they do, but on the other hand people who prefer to steal because they find it easier than working for things just want to steal.

As a step mother of a 16 year old girl with cleptomania, I understand many of the emotionally draining and frustrated feelings
That go with living with a person you can never trust. You are like a prisoner in your own home. You are not free to live comfortably the way you should feel in your own home. You are on guard and doubling your efforts to make sure valuables are locked up or out of sight. Sometimes You may feel guilt for having to protect yourself this abnormal way in your own home. Sometimes you feel helpless or angry or both.
Even after counseling and heart to heart talks, sometimes the perpetrator feels no remorse and brags of doing it again if
She feels like it because she likes it. You are dealing with not only child that is at a rebellious time of her life but one that is
Mentally ill. Continue counseling and know that soon she will be grown up and out of your household and you would have done everything within your ability to help her. Just know that because she grows up, does not mean she will overcome this issue however.
We had to send her home to her own mother only to learn that 1 year later, her own mother kicked her out. She is now staying with an Aunt... not sure how long that will last.
If anything, get counseling for yourself also, to help you cope and deal with this difficult situation.