I gave her all the best armors but the only piece she refuses to put on is the Elven Shield. Any way to bypass it or she is incapable of equipping. But all the rest of her armor is Orcish and I don't see whynot.

I don't use companions very often, so not sure about this. But it sounds like maybe she doesn't use Light Armor?

Do you play PC or console?

Lydia is a Heavy Armor user. Unless you give her a light shield that has more DR then her skills and perks give to a heavy armor shield, then she will wear stock shield.

In other words, unless you can improve glass, she is going to go heavy armor.

I think the numbers the game shows for armor rating include the effects of skills, so even if it shows the elven shield is better in the inventory, it could be worse for her if her heavy armor skill is higher than light and yours are the opposite.

Lydia (and the other Housecarls) specialize in Heavy Armor. And so will tend to use heavy instead of light.

Orchish is Heavy Armor. Elven is Light Armor. So that's why.

yer this ^^

I tried to give my female houscarls all forsworn armor as it is the most revealing and I like my staff to dress well for the job. I was disappointed as they didn't play along as they both like heavy armor

Try Falmer armor. Or Ancient Nord. I got Lydia to wear Ancient Nord, even though it has a lower base rating than her standard steel. Maybe because it's considered Daedric and is thus "higher" in the hierarchy of armor? Anyway, she looks good in it.

a-ha. Sounds good. I'm off to try that one

Hopefully the housecarl in Solitude will also oblige. It is my new staff uniform (only the females, lol)