Is it always a good thing to be diagnosed with something?

My DIL is a bit of a helicopter mother. She is a very good mother but she does hover over her children all the time. In her defence I was probably much too laid back. My 15 year old GD went through a phase of self-harming - not badly and she hasn't done it for nearly a year now - two other GDs did it when they were young but both fine (one of them is a very high powered accountant with three children). The problem is that my DIL is convinced that the girl is neuro diverse and is trying to get a diagnosis for this. I'm worried that a label like that will stick and make life more difficult for her in the future. My son just hides his head in the sand. I haven't said anything to my DIL as she doesn't take kindly to any criticism. I don't think I'm expressing this very well but there seems to be a modern tendency to label people with ADHD because they can't (or don't) concentrate, dyslexia when they are late readers, dyspraxia when they find it difficult to tie their shoe laces. Apart from anything else it takes away from people who really have these conditions. Does anyone else have experience of a similar situation?