Hi I think if you are unsure about this ladies hair and she has a lot of white in it
I would try and suggest that she does not have an all over colour ,as it may be too severe for her
I would try and talk her into some lowlights and a few highlights where is is darker to even up the colour
people who have a lot of white hair tend to be shocked with an all over colour
If she really wants it then you could go for something like a 7/73 tint with 6%
by wella
and then put a few highlights in it and around the front a bit like Jane Fonda ,
but that is a wella tint I don't use your brand soz,
if the hair is short and all natural its on the roots and straight through all over