The same happened to me when my son was 5.5 months. He went into anaphylactic shock when I gave him yoghurt, he had urtcaria afterwards for weeks on end which left eczema in its wake. It took months for it to go.
Unfortunately its not just milk hes allergic to, but milk, eggs, banana, lentils, soya, peas, pears, raw potato, sharon fruit, nuts, spinach, wool, feathers, all meats, worse with chicken and beef, Aveeno cream, Oilatum, lanolin.
Sometimes eczema doesnt go 100% and you just have to manage it.
Consider that you might find a better cream for her, different creams work for different babies. Im currently using a lovely one called QV cream. They'll send you a free sample.
Also, dont bath her more than 2-3 times a weekand dont use any soap at all.
Allergic babies are sensitive babies, you have to consider everything.
Washing powder is another one, def no conditioner, extra rince. We use soap nuts which helped considerably.