Hi
Was wondering what is a good place near winterthur, to buy english kids books for a 10 year old.

Probably not what you are after but we get ours online from the U.K. from the Book Depository.
Postage to Switzerland is free.

Do you mean "IN Winterthur" or near?

Personally Zurich to me is 'near' Winterthur, and in that case, a direct train to Zurich HB won't take too long.

Slip down Bahnhoffstrasse to the "Orel Füselli" store..... It's an ENGLISH book shop, and will have all sorts of things there to entertain a 10yo.

a quick cup of coffee, and pop on the train home.

Yes Orrell Füessli, or Thalia Vogel, they're both on Marktgasse and have a small selection of English books. But I admit I usually order mine with amazon.co.uk