Hi all, and thanks for your replies!
@RedSky: Thx for your advice; I'll keep what you said in mind. It's OK if the food is not hot, I just don't want DD to have cold food, warm is fine with me.
@Hersetta: I won't use it for soup, only for things like pasta, rice, couscous, etc. How much pasta can you put in a 290 ml I wonder? I saw one this morning at Boots and it seemed absolutely tiny and that's 380ml! I may need to look for pics online of that particular flask with food inside so that I can visualise how much can fit in...
@Betty: thanks for the link; I lie Wilko's products but I want to buy something a bit colourful to make it a bit different from the adult ones at home.
@irvine: lol, do you have a problem with Japan? Why not type it? 
I would love to buy from there but the delivery cost will surely be high?
@All: what do you think of this one?
www.amazon.co.uk/Pioneer-Vacuum-Insulated-Leakproof-Flask/dp/B005SZHTWE/ref=sr_1_sc_1?keywords=pioneer+pink+flast&tag=mumsnetforum-21&ie=UTF8&qid=1541608533&sr=8-1-spell