In episode 20 of Attack on Titan, how does the Female Titan have 3D Maneuver Gear after regaining human form? I remember someone saying (not sure which episode, though probably the same) that Eren lost his 3D Maneuver Gear after exiting his Titan form. I also remember seeing that myself, after exiting his titan form every time except the 2nd time he does (He had no gear on him, then, to begin with). So how was the girl inside the Female Titan able to have 3D Maneuver Gear on her, as well as a Survey Corps coat?

Note: I have finished watching the anime, but I have not read the manga. Please don't post any spoilers for me. Thank you :)
This answer pretty much explains everything.

Whilst riding on horseback


  Zoe- Erwin, why did you order Levi to resupply? There's no time to
  waste.
  
  Erwin- The female-form Titan was eaten. But did you see the person
  inside get eaten? I didn't.
  
  Zoe- You can't mean-
  
  Erwin- Ah, yes. If your original hypothesis was correct, they can
  still move to a degree after regaining human form. If they'd prepared
  3D Maneuver Gear in advance...





   Erwin- The person inside the female-form titan is wearing our uniform right now... The enemy is now camouflaged as one of the troops.