Aurora-- one of the people that directly trained under Megawoman in The Sanctuary. The people under Megawoman might have been close while they were still on their little island, but as soon as they separated in their own ways and left, they became distant– strangers, even.
And since Megawoman didn't mind or didn't care, none of them took the initiative to contact one another. She might have taken care of them for a while, sure. But if there's anything that Megawoman didn't have, it was time.
It was evident even through her own son, Empress thought. She tried her hardest to be a mother, sure– but any effort she made was wasted due to the fact that she didn't have time. Empress knew she got pregnant almost two decades ago and only found out recently that in an almost twisted fate, her son became friends with Darkday in Mega Academy.