I have Zrhana as a companion now and I have given her some armor. I have seen her use the weapon I gave her but it does not show her wearing the armor when you look at her. Do they use the armor you give them are do they not need it? Also there is no way to show their health, so just wait till they are knocked out to give them health? Can't use armorers hammers on them either. Do they use the weapons till they are useless? I was wondering because I gave her my mage sword which is pretty good.

I figured out how to repair her weapons. Just take the back from her and fix, then give back again. The only apparel I have seen damaged so far was the hood I gave her. Maybe because I am in the front lines more?

Edit: I have five companions now and have them pretty much figured out.

I have mot played Morrowind in some time but i did play a LOT when I did. I used the Witch Girl mod by Emma. I could arm and equip her, however all companions I used seemed to degrade their gear much slower than I did. Your specific girl, couldn't say if she works right or not, but the mods I ised did use the gear you gave them.