Op, agree everyday weekday cooking for DC can be very unrewarding and tedious but planning ahead definitely helps. If you allocate a food group or style of dish to each day of the week, it stops the dreaded rabbit in headlights feeling at 5.30 pm. You can also calmly point to one particular dish on the list when asked "what's for tea?" and because you are confident about it, the family don't protest too much (in theory). Just create loose categories for each day with a selection of three or four dishes under each of those, so then you know if it's Friday, it's fish, so it's going to be one of following: ie fishcakes, frozen salmon steaks in foil parcels with vegetables,, fish fingers, tuna bake etc.
Or Saturday = fakeaway eg breaded chicken and oven chip & peas, stir fry, chicken noodles, meat balls, burritos
Sunday: "roast" but you could do simpler version with roast chicken, or lamb chops, frozen Yorkshires or frozen roast potatoes, peas. Or cook a small ham in natural apple juice.
Monday: cold cuts from mini roast (easy) and tray baked veg or frozen vegetables with new potatoes or rice, small individual shepherds or cottage pies made in ramekins, shredded meat and veg in warmed wraps, or hot pork buns etc
Tuesday: vegetarian 1 with pasta or rice eg pasta with pesto or tomato sauce, or hidden veg, egg fried rice, veggie chilli, nasi goreng, pumpkin or mushroom risotto,
Wednesday: tray bake night (easy) eg sausages, or marinated chicken legs with roast veg or frozen peas and sweetcorn, rosemary lamb chops with peppers, lemon potatoes etc.
Thursday: vegetarian 2 eg veggie pizza, sweetcorn fritters, veggie burgers, chickpea fajitas, pitta pockets, thick lentil soup with etc
Create a list of breakfasts and weekend lunches too: pancakes, cheese/baked beans/ scrambled egg on toast, sausage rolls and batons of raw veg, Cornish pasties, toasted sandwiches.
Annabel Karmel has some good recipes for DC. And Dorling Kindersley do some really excellent step by step "how to cook" books for children, which contain really excellent recipes for children and adults alike. The children might like to become involved themselves at weekends. Jamie Oliver's simpler family recipes are good too.
Good luck.