10 and 8 year old here:
b - porridge, w/bix, various cereals - sometimes fruit or some toast. Sometimes scrambled egg or crumpets. Variety really!
L - usually sandwich or bagel with ham, tuna, peanut butter, marmite, smoked salmon (try to only have ham twice per week). Then add 2x fruits/veg, sometimes crisps, yogurt (vary frubes or plain), sometimes a baby bel, or a small biscuit. That’s for packed lunch. At home it could be beans on toast, scrambled egg , soup, pasta….
D - at after school club is limited and often pixza/pasta etc. at home it will be a chilli, spaghetti bol, sausage and mash, salmon and rice, roast, curry, jacket potatoes, meatballs, homemade chicken burgers, not homemade beef burgers, fajita type wraps and salads.
snacks - fruits, veg, biscuits, cake if we have it, ice cream. Try to do healthy first. Rice cake and peanut butter is a good one.
ETA - drinks: water, squash, milk and fizzy for a special occasion or a Saturday sometimes.