Most kids will not learn the piano for very long. They quickly get crushed under the nightmares of scales, metronomes and sight reading. It is important to build confidence and get them off to a fast start. Instead of burdening them with the trial of fire by scales, metronomes and sight reading you would do well to follow this well tested methodology.
1. Chromatics and only chromatics. No scales for three years.
2. Never use a metronome. Instead suggest the half note lasts a little longer than the quarter note. The kids can work the rest of it out for themselves.
3. Sight reading is over emphasized. They can learn to play by ear and by rote in the beginning.