No, I didn't purposely choose a bad pic of U3. That was just the best pic showing Chloe's facial features I found on Google Images, and didn't feel like browsing a bunch of pics on another site to find a better pic of her, especially because she really didn't have a large role in U3.
And that's not how Chloe looked for most of U2. That's just one bad pic of her.
Seriously, go back and use Chloe in U2's multi, then use her in U3's multi. The character model was definitely downgraged.
By the way, unless my memory of U3's single player is way off, Chloe never wore that red jacket in the single player. So that's not a pic from the final version.
Edit: Apparently she did have a red jacket, so I was off on that. But Chloe still looks off compared to her U2 counterpart. It's most noticeable in the multi, but can also be seen in the single player.