I think I was a little unclear — only one thing can be a weapon, so it would be strength OR armor, and she wouldn't be moving the enchantment. But you're allowed to get clever with the evolution, IE, eventually wearing the armor will make her physically stronger as well.

Another option is to actually change her weapon in-game, but in that case she would lose contact with the armor (if that was her first weapon).

And finally, being able to summon armor is definitely something that could be evolved with it! Also, in the case of a mission where bringing along the armor is impractical, she could potentially bring along just a piece of it, and wearing that small part would endow whatever powers it usually grants her.

Basically, as long as it's just one weapon that gets picked, you can pretty much take it where ever you want.