|What kind of plants are|
|I've found that creeping, crawling flowers work best because they're not bothered by the girls' scratching and digging. Hardy geraniums, yarrow and lady's mantle, rose campion, calendula, borage, and love-in-a-mist are prolific self-sowers, so at least some of their seeds survive the scratching and pecking.
What else? Low-growing salvia, maybe coral bells. You may have to temporarily fence your girls out until the plants become established and are not so susceptible to damage. Good luck with your garden!