Capacity can be a slippery thing @Alora - it isnt an all or nothing thing. You have to take each decision individually. However, if she is unable to consent to treatment due to loss of capacity, then there will be many, many other things that she will not have the capacity to decide. When mum had a cataract removed she still had the capacity to consent, even though she had no capacity to manage her finances or arrange a POA (I had deputyship on that basis) and she had no capacity to decide where she lived (she was in a care home with a DoLS)