Thank you for the question. The photo of the rash can go for eczema.
The rash in eczema is usually itchy, and aggravated by scratching. Persistent scratching or reaction to certain creams applied can cause the rash to be recurrent or persistent, so your mother should refrain from scratching as far as possible.
If the rash is still persistent despite treatment, you may want to consider seeing your doctor/dermatologist to rule out an underlying cause for the persistence, such as a fungal infection or allergic contact dermatitis.
Further tests and adjustments to her treatment regimen may be necessary.