Hi, I'm not a nutritionist btw. Not bad and I've seen worse, but there are definitely some improvements you can make.
I think general guidelines are to aim for a mixture of carbohydrates, protein and fruit/veg at each meal. Carbs = pasta, rice, bread, potatoes, polenta etc. Protein = meat, fish, cheese, yoghurt, nuts (if allowed), seeds, tofu, lentils (which also contain some carbs btw). Also a little fat needed. Carbs fill them up, protein keeps hunger at bay. The fresh veg etc provides nutrients, vitamins, fibre etc. You should also look at wholemeal carbs for the 5 year old (but not the 1 year old).
Your 5 year old's snacks look good but maybe add a plain cracker or similar.
Puddings - they don't need a proper sweet pud every day. Our children have yoghurts, fruit, fresh fruit compotes, and we only have a 'proper' pudding about once a week. The puddings you mention are quite high in sugar I would think.
Breakfasts - quite calorific. Croissants have an incredible amount of fat in as do brioche. They're saved for special treats here. Apple juice is very sugary (natural sugar yes but still makes your blood sugar rocket - children generally have their juice watered down a lot with tap water). So nutella + apple juice is a serious sugar rush (especially if it's white toast too!) which will be followed by lethargy later.
What about sugar-free cereals, muesli, porridge (in winter), yoghurt, fresh fruit, wholemeal toast with marmite or a v small amount of jam etc.
Evening meals - the fish and chip one sounds a bit short on veg (which doesn't include potatoes). It's also a bit too processed (so probably high in salt and saturated fat), but obviously not everyone has the time, skill or money to cook from fresh daily. Spag bol is great if it's got hidden vegetables but a bit short on veg if it doesn't (don't count the tomato).
As for the 1 year old - that's a heck of a lot of milk! Assuming she's a decent weight she should (according to our health visitor anyway) be down to 2 200ml bottles a day (first thing in morning, last thing at night) at 1 year. Change the milk 'snacks' for cubes of cheese, cucumber sticks, pieces of fruit, unsalted rice cakes... If you give her porridge or similar for breakfast that will have milk, plus cubes of cheese, plus a yoghurt then you're probably fine to cut the formula down to 2 bottles a day, but withdraw each bottle a bit at a time (we go down 30mls every couple of days), allowing her body and food intake to adapt (otherwise you might have a pissed off, hungry baby).
As for your diet, you can probably get away with brioche for now, being pregnant. How about milk with cereal, cup of milky cocoa (i.e. made with real milk) for the calcium. If you're at any risk of getting gestational diabetes then cut out the orange juice or at least go half and half. You could possibly add some calories, but I don't know your weight etc..
Hope that helps, happy to give more advice. Remember I'm not an expert!