I'm not sure where to ask this on the forum so I hope I'm in the right place and someone can help me out. Here is my question:

My wife (we are separated) has a daughter by a previous marriage in her 30's who either calls or texts her Mother throughout the day without exagerrating every 5 mins. This has always been her behaviour. The daughter as a child used to place photos of herself on her Mothers dashboard when she was young so her Mom could see her all day. Christmas presents from the daughter are usually a large photo of herself to her Mom. Some days the phone rings almost non-stop. The Mother feels this is normal between Mothers and Daughters. I've known many Mom's and Daughter's in my life but I've never seen this type of obsession before. First of all, is this normal behaviour? If this is some kind of condition, what is it called? Thanks.