The High Septon says she'll have 7 judges:
A sacred court of seven judges shall sit upon this case. Three shall be of your female sex. A maiden, a mother, and a crone. Who could be more suited to judge the wickedness of women?
I'm assuming they're meant to represent the Seven, so:
The Father: My gut tells me it's going to be the High Septon himself, as he's "the Father below"
The Mother: No idea. I wonder if an actual mother would be chosen
The Warrior: I think Ser Theodan the True is a given, being the Commander of the Warrior's Sons
The Crone: I'm guessing one of the gazillion old septas that are always in the Sept
The Maiden: My guess is Tyene. I made a thread about her possibly being one of the acolytes serving Cersei here, but I think the quotes still apply here:
Lady Tyene smiled at that. Her gown was cream and green, with long lace sleeves, so modest and so innocent that any man who looked at her might think her the most chaste of maids.
“Why not? White suits my coloring. I look so … pure.”
And that leaves us the Stranger and the Smith (Tobho Mott, perhaps?), any candidates for them and the others?