Try using a rear-light as a torch when you get out of bed. You should see enough to have a visual reference and the light won't be powerful enough to disturb barakta. Won't clobber your night vision either. I also have dodgy balance and it works for me.
I just press the button that lights the LED fairy lights around the periphery of the ceiling to 5% of maximum brightness. That's enough to not fall over (giving a 'horizon' makes up for low illumination), but not enough to see through closed eyelids. Barakta will sleep through it, unless she's not sleeping properly anyway, sees the lights on and gets confused and starts asking me why the lights are on (and then can't see well enough to read my response, requiring further waking up).
We have a similar arrangement in the bathroom that comes on automagically when the motion sensor is triggered between sunset and sunrise, giving enough light to find medication, check for Big Hairy Spiders™, see if the toilet's flushing, have a bath when you've got a migraine, etc. without blinding yourself. Something which I can thoroughly recommend.
The bigger problem is finding clothes in the morning if she doesn't want to get up, but 'twas ever thus.
