Should my Mum have had physiotherapy for her arm?

my mum had a stroke about 3 years ago,which affected her left side.with the help of physiotherapy my mum was able to walk with the help of a stick.she didn't receive any help for her arm which was paralysed .my family were told that there when she was at home a physio would call to continue with exercises to strengthen her left side.just when the health team called out.they said that there was nothing they could do to get her arm moving again.now my mums arm is just left dangling lifeless by her side.she does have feeling in it but she cant use it.i know that 3 years later is a long time for me to be asking this question.
its just at the time ,all I could think of was just getting my mum used to life after a stroke.also I thought they are the health professional's they must know what they are doing.just as my mums getting older and frailer at 78.her arm is quite heavy.so should she have had physiotherapy for her arm?