It's really quite a strange thing to say to a parent - especially the use of the word kid - not professional at all. Every child is different, while she may not be as focussed in certain areas, she might excell in others, it's very wrong to use such a comparison. Perhaps DD is actually bored and needs more stimulation - is she close to being old enough to move up to the next room - maybe a change is what she needs and new and more stimulating activities, etc.
My staff only every address concerns to parents in a very tactful way and not without passing by me what they are concerned about first. Eg. GL had a concern a child in her group may not be hearing clearly, so she asked how she should adress it to Mum - in a tactful and polite manner.
Thing is, my staff are all anti using drugs for 'controlling' behaviour - so we'd never go down the I think your child has ADHD and needs medication path... I suppose it depends on the individual staff members convictions.