Well most kids grow out of it, however my DH has still got it (24) and it can get bad. You can use E45, Oilatum or diprobase on it, its not a quick thing you have to apply many times a day to get in to settle down again, and then maybe just do it morning and night. Dont use anything with perfume in it, DH can only use tescos head to toe body wash (its for babies technically), timotei shampoo still stings but its the best he has found so far. Hot/warm water will probably worsen it, but you have to wash her. Check that she has no food allergies as well, and if she gets hayfever make sure you give her something to settle her. My DH's eczema flairs up if something stresses him, so hayfever does it or work (though your toddler wont have that one) or summer weather.
Betnovate has steroids in but the others dont as far as I am aware. Oilatum is horrid stuff, when DH eczema gets bad he is meant to use the bodywash stuff but he hates it soo much he doesnt, but you can get it for babies too- bodywash, moisturiser, and well its not bubble bath but you put it in the water.
Hope this helps a bit.