There is no canonical Circular Gallifreyan. However, you are not totally out of luck. In 2011 a fan by the name of Loren Sherman created a system that has been used by the show on official merchandise including a [comic][1].

[![enter image description here][2]][2]

> Gallifreyan is the fictional language of the Time Lords, from the TV show Doctor Who. On the show, it's usually just random circles. I'm not affiliated with Doctor Who or the BBC, but back in 2011, I created a "Gallifreyan" writing system. It somehow got really popular among fans and eventually made its way onto the show.  
<sub>[Sherman's Website][3]</sub>

His system is based on the Gallifreyan depicted in the show. But would not be able to decode any of the Gallifreyan shown.

> All forms of Gallifreyan [..] are based off of Gallifreyan in the show Doctor Who. They're fan made however, because the Gallifreyan in the show cannot be decoded because there is simply nothing to decode.  
><sub>[Omniglot | Sherman's Gallifreyan][4]</sub>

He wrote up all the rules into a guide you can view [here][5]. And another fan took these rules, and wrote a translator you can see [here][6].

Using this, your first image is close to what the translator outputs for "Amy". But here are both.

**Amy**

[!["Amy" in Circular Gallifreyan][7]][7]

**Amelia**

[!["Amelia" in Circular Gallifreyan][8]][8]


  [1]: http://tardis.wikia.com/wiki/11DY3_4
  [2]: https://i.sstatic.net/9TbSQm.jpg
  [3]: http://shermansplanet.com/gallifreyan.html
  [4]: https://www.omniglot.com/conscripts/shermansgallifreyan.htm
  [5]: http://shermansplanet.com/gallifreyan/guide.pdf
  [6]: https://adrian17.github.io/Gallifreyan/
  [7]: https://i.sstatic.net/9pVA6.png
  [8]: https://i.sstatic.net/g8AK3.png