Having dealt with eczema myself most of last year, there wasn't any cream or lotion that helped. Coconut oil or olive oil is soothing to the skin, but of all things, an ice cube gave me the most relief. In the end, large doses of vitamin b complex cleared things up. This is the stress vitamin and is water soluble so you cannot overdose as with fat soluble vitamins and minerals.
It is best to address the underlying cause of the eczema though. When the liver is overworked, it sends toxins out the skin. It could be the major allergy culprits like wheat, dairy, soy, or nuts. Or it could be food additives like msg, food dyes, preservatives, etc. It could also be a gut imbalance, especially if she was recently on antibiotics. Reactions will usually occur anywhere from 2-18 hours after consumption. Start keeping a food journal now. Hindsight is always 20/20, so eventually you'll see a pattern that may surprise you.
Good luck!