While Su handled things within the Genesis building with the representatives, Rise was already off. She had a total of five light dragons with there. Two elders carrying children within them, and three who had left others to handle things so that they could act as guards for the two vulnerable dragon elders.
She could understand that Walker would be coming as soon as he was able. especially since the idea that another elemental bridge to the elemental planes was open he would want to test it.
There was also the chance that another true sage would be coming through. They had yet to hear or meet the light true sage, someone that Rise both wished to meet and worried that she should not meet at all. Not because she feared them but because she was unsure.