Avoid contact with detergents of any kind to begin with. It's a contact irritant dermatitis a d it will aggravate if in contact with chemicals likes dish washing soaps. Being Covid +ve recently hasn't got much to do with this condition except that her immunity will be low.
She will recover with basic cream applications, preferably consult with ur Dermatologist before using any creams.
Health Tips
Keep the hand well hydrated. Use non powdered disposable gloves once the hand gets better