Unbrushed/combed hair

If I brush my DGD's hair, it looks beautiful, silky and gleaming - and within 5minutes, it looks as though it hasn't seen a brush in weeks..!
I have no idea what happens, but it looks like rats tails. If she was my DD, I would take her to have a nice short cut - but she doesn't want that, and her Mum (my DD) agrees - so it's none of my business ?

Around here, at least, (apart from poor DGS sticking up hair), most of the children have very tidy hair. The girls often have those immaculate braided into the hair plaits. (I don’t know what they are called). Yesterday, as I was at the hairdresser, a young mum came in with her immaculate little boy to have his already short, neat hair trimmed!

I didnt bother putting my dgd through the ordeal of hairbrushimg today or teeth cleaning as she was going home after sleepover. Her mum said she would see to it so no probs

My younger DGD starts the school day with nice plaits or bunches but they never stay in until the end of the day!
It is long and silky and looks lovely for 5 minutes after brushing.

We weren't allowed to have hair which touched our collars when I was at senior school; if it did it would be tied up by one of the teachers (very roughly I might add).