It is natural for children to forget. Do not scold them, as this creates a negative association. Instead, if they remember while still at the table, they can say it then. If they remember later, a simple "Alhamdulillah" suffices.

This is a profound teaching moment for kids. We thank Allah for physical fuel (food/water) but also for spiritual fuel (Islam). Food keeps our body alive for a few years, but Islam keeps our soul alive forever.

Yes! For very young children (ages 2-4), simply saying "Alhamdulillah" (All praise is to Allah) is perfect. As they grow, you can add "for the food" and eventually teach the full Arabic.