Here is the temp fix I have found out after some testing:
- If you give her a good bow (Elven, Glass, Ebony etc.) which should definitely be an upgrade for her she will only use it for 12 shots (her hidden quiver of Iron Arrows is 12.) then she will put it away and start fighting with melee weapons/fists.
- If you give her a good bow and good arrows too, she will refuse to use them together, instead she will only use the good arrows with her default Hunter's Bow.
-If you take away all weapons from her and send her home and then get her back and give your good bow to her again, her hidden quiver of 12 Iron Arrows will refill and she will use the good bow again for 12 shots. You may only need to send her back not taking away to bow and her hidden quiver may still reset. I have not tested this.
TLDR: So currently she will either use good arrows you gave her with her default Hunter's bow or she will use a good bow you want her to use but only when you supply her with Iron Arrows.
- Currently the only way to make her use the good bow you want to give her consistently is to supply her with Iron Arrows (this is because her default hidden quiver consists of Iron Arrows as well). This way she will use the stack of Iron Arrows along with the good bow you gave her as long as the stack lasts.
- I Also noticed that if she gets shot by better quality arrows, the arrow will be put into her inventory (same way if you shoot a mob with your arrows, some of them can be found on their corpse upon looting) and she will immediately switch back to her Hunter's Bow as long as the better quality arrow remains in her inventory. Also I noticed that she will never run out of arrows that got shot into her inventory by enemies. If you want her to use the good bow, you will have to manually remove the 1 piece of better quality arrow from her inventory between fights.
- This bug seems to be appearing on all the Followers
Okaaay, that's bizarre. I wondered why she wasn't using the Orcish Bow I gave her, yet she's happy enough to swing around a Dwarven Sword and Shield. I gave here a whole bunch of Steel Arrows, too. Maybe I'll take them off her and see what happens!
When I made Whiterun Thane and she joined me, I was pretty excited. I though cool, my dudes got a friend, a warrior-woman to follow him round. Excitement has turned to disappointment at the bad pathing, frequent disappearance, frequent running-in-front-of-my-two-handed-fireball and complete lack of equipment control.
Come on Bethesda...I know you can do better! You claimed to take notice of some of the mods people had made, why doesn't it show? On this as well as other things.