As Salvo said, Cam-Cam should have quite a bit of AC on her. Seelah also works. Since you're a paladin yourself, maybe consider turning her into a Skald or Bard. I haven't used Skald but other people in the thread say they're really good. As a bard, I gave her 2 levels of paladin and the rest into bard. She can then buff the party with spells and songs and can cast mirror image on herself. If you want to cast in combat you'll need to keep her in light armor, but if you don't just slap a plate on her, remove it to cast buffs outside of combat, put the armor back on when you're done.
Give a reach weapons to Sosiel so he doesn't get his ass killed every 5 seconds - Soulshear works quite well - and also consider using Reduce Person on Regill, but he should generally be fine if you slap some Barkskin and Magic Vestment on him as he has high dex and benefits from armor training.
If you feel your MC is also squishy, grab Soulshear or another reach weapon for yourself, or fight enlarged. Maybe consider putting some points in use magic device and have Nenio craft Mirror Image scrolls?
And grab someone with Stealth or you're going to yeet yourself from the constant random encounters, some of which can be quite rough.
Wintersun should be partially doable without much pain at lvl 10 just
