Thanks for the replies....i feel guilty now, and thought i had provided a lovely little set-up for my girls...think i will have to look at extending the run somehow...I cant really go over the top with it, so what size would be more acceptable...I certainly couldnt bring myself to re-home 3 of them.
As things stand now, the run is covered in wood chip, so i normally throw a few mealworms in and then rake it over, so that gives them something to do when unable to free range. There are 2 perches in the run, which are set at slightly different levels, but not too high.
The girls manage to dust bathe in the run, and also their favourite spot in the garden, when out.
Will start hanging a cabbage in there as well.