We will only be going for two days, food will be included, so the money we take will just be for buying souvenirs and pocket money for DD who will have just turned 8, How many euros should we take with us? And how much should we allocate for DD?
depends how much you are looking to spend and how much you can afford.
I have gone and spent very little on souvenirs less that £150 for the whole trip, now I tend to allocate £100 per a day but I save for it all year and some of that will go on the odd cup of tea and bottle of wine with dinner.
Prices are similar (but usually slightly cheaper) to the Disney store in the UK. You can have a look on there for guidance of what you money can get you. DC get £20 each per a day to spend on what they want (included in the above). Hoodies are great value, mugs and china wear are fantastic, occasionally you get a good tshirt bargain, toys are equivalent to here and older size dressup outfits are better there (but not younger). If you went for between £30 to £40 each your Kids would be able to get 1-3 large ticket (hoody, small to medium cuddly) items or lots of smaller items (like the pin badges).
But you could happily halve that and just focus your childs attention on one nice souvenir.