Delurking to give my take on our friend's kids. Hetharti and Atharti have been suggested, but what came to my mind upon reading the update was different. By now several different posters mentioned Halétha, and I think she really is quite likely. Consider:
Fact: No known myth in the old world tells of Ranald or Shallya having daugthers.
Ergo: One might expect any such daughters to be minor goddesses.
Fact: The hedgefolk are divided into several groups, divided by geography and religion. We know the religions of three of those groups, who worship Ranald, Verena, and a minor goddess called Halétha.
Theory: Ranald's daughters are patron goddesses of the hedgefolk, one of which is erroneously worshipped as Verena, her maternal grandmother.
Question: If so, is one of the trickster's daughters intentionally posing as Verena?
Question: If so, is she playing a trick on her followers, or are her followers playing a trick on outsiders?
Experiment: Set the coin to The Father face, and take an action to attempt to bring the hedgefolk into the waystone project, which we wanted to do anyway. For extra credit, take an action integrating ourselves with house Tindomiel on the same turn, which will let us test the second theory as well.
Alternatively:
Theory: Halétha is a patron goddess of (some of the) hedgefolk, while other hedgefolk are sponsered by her father and her grandmother. The second twin is unrelated to the hedgefolk.
Fact: There is a minor goddess of fertility called Haleth, which sounds suspiciously similar to Halétha (I'm basing this on the wiki, no idea if this is canon to the quest).
Theory: Halétha is the twin that takes after Ranald, and her sister Haleth takes after Shallya.
Experiment: As before, but also pay a visit to a shrine to Haleth or something. Honestly not something I suggest we spend AP on - I say we start with Halétha, and if that turns out to be correct we can see about Haleth.