For me what helps most with navigating steps is knowing where the edge of the first one is (way more important going down than going up) and knowing how many of them there are.
It could just be me, but steps that have every edge marked can feel visually disorienting/overwhelming when I'm looking at them and trying to visually navigate my way down them. So if I know how many steps there are, I just find the first one and go.
To that end, you could tack down something like
$1 along the edge of the first and last step. You could even paint it with a high-contrast/non-slip paint if you wanted to (or if she wants every step marked, you could do that too).
Also, motion-activated ambient lighting (so it doesn't cast weird shadows) around the steps can help a lot.