The good news: Although this is odd and eccentric behavior, the limited nature of it allows a rule out of a more serious issue. Simply said: It's odd, for certain, but not harmful or cause for worry.
If her reality testing was not intact, which means this was far more global and extended into other objects or situations, there would be a need for greater concern. But here, the behavior is limited to one situation and has affection in the emotions shown.
In our 40's, especially with women, a loss of emotional contact with others occurs more markedly. Children grow up and are less needy; menopause approaches or arrives, and regrets of an emotional focus take place. There is emotional loss.
Sometimes old memories/dreams and fantasy are held onto in what appears to be a dysfunctional way. But these are coping mechanisms, and kissing a photo, even talking to it is a way that some people express these feelings and cope.
If this behavior starts to extent to other objects or situations then I would be concerned. Until then; it is an eccentricity of her development. Odd, but harmless. Steven
I was not aware that the behavior had been quite this long term.
Typically these types of behavior do start during midlife with the changes and emotional losses that occur; however, as this has been ongoing for many years, the specific reasons can be more difficult to pin down.
Clinically though, there are some patterns that are common to this type of behavior.
The most likely motivation for this is a trauma of some type. Trauma of an emotional (even sexual) nature can be tied to behaviors like this For example: Unresolved feelings of loss, or grief can start a pattern of behavior that helps deal with the emotions experienced during the trauma. It is a way to express feelings without directly dealing with them, much like working out an exercising allows frustrations that are not specific or even conscious to be worked through.
Without a face to face assessment it is very difficult to say what the key past issues were, but I can tell you that with past clients; loss of a pregnancy, sexual assault and even separation and marital infidelity can cause an expression such as you see here.
If this is so, the best approach is to encourage mom to talk with a counselor as this behavior, although innocuous in an d of itself, can be a sign of some other unresolved issues. Steven