I use the skatingsafe ones under a length of tubigrip (elastic tubular bandage) cut to approx twice the length of the pad. Pull tubigrip on so top edge is about where you want the top edge of the pad to be; place pad over tubigrip; then holding pad with one hand, fold up the excess length over the pad. The pad can't slip down past the fold at the bottom of the knee.
I do think the skatingsafe-style pads are the best around as far as protection goes because they protect the sides as well as the front, but until I started using the tubigrip I found them inconvenient. However, using tubigrip to hold them on means you can use them without needing the compression of tights, and the pads are quick and easy to remove temporarily. You can also get tubigrip in skin colour, which visually "disappears" quite well if your DD is wearing a practice dress or skirt.