Hi...THANKS for your query.
There can be multiple causes for itching.
It can be xerosis due to age and dry weather conditions.She can continue with Cetaphil
formulations made for very dry skin
like Cetaphil Restoraderm and olive oil. Cetaphil should be used 3-4 times on entire body including just after bath.Orally she may have anti allergies like Tab.Allegra or Cetrizine
to control the itching.
Watch out for bed bugs .They tend to occur commonly.
Wollen clothes cause allergic reaction
in some people ,so that needs to be taken care of.
In case she has any other skin lesion , an examination with a dermatologist
should be made.
Hope this is helpful..Take care!