This was something they cut from the anime, likely so they could end last episode on a cliffhanger.
*Possible spoiler warning*

The genome act cause Emma to fear that Aries would find out she is not her daughter. She was going to tell her when they went to the center to submit their DNA. This was something she talked to the vice principals about.

*Later spoiler*

Just wait until we find out who her biological father is.

They haven’t said anything about Aries’ father. In fact, aside from Luca and Ulgar there has been no mention of any of them having more then one parent.

This series is just so damn great, it’s been a long time since we got a good space adventure show and it’s partially a mystery one at that.