I would say no. If she has changed that isn't your fault. If you are receiving multiple complaints about her via your recommendation you may want to consider letting her find her own way.

We had a good experience with a former nanny who worked
for us for over 3 years. We parted ways amicably about 2 years ago.
Since then I have served as a reference multiple times because
I was her longest employer. But she can't hold a job or mom's even call
me to say she is nothing like I described, wouldn't do things they asked,
or was so aggressive about salary instead of the job that it was off-putting.
I feel I am giving an honest assessment of her time with us but maybe she
has changed. Should I continue serving as her primary
reference? I have tried to give her interview advice before
but it clearly hasn't helped.