In Heroes of Thantopolis, the protagonist's mom is really important - because the protagonist misses her a whole lot!
While he came to Thantopolis without his memories, Cyrus knew he loved his family - he just didn't know why. It wasn't until Ch5 that he finally remembered who his mom was.

.... and then he spent the next couple of pages crying since he misses her so much!
Cyrus's Mom is not just a background character in the comic... there's more to her than just what Cyrus remembers... but you will have to wait and see what that means!
As for Helene, her mother gets briefly mentioned at the end of Ch5:

Helene and her mom do NOT get along. Both of them are sneaky, controlling and manipulative goddesses... and there's just not enough room in this world for both of them. Makenea views Helene as somewhat of a turncoat, changing loyalties to gain more power. Helene thinks her mom is a grade A jerk. While Makenea doesn't play a big role in HoT, she is a main character in Cyrus's second story, Threshold.
That's all the moms in my comic! I find it interesting that parents play such a big role in my stories. Probably because my parents play a big role in my life and I'm fortunate to be very close with them.