I have an out there idea, i think it's Veil, she was adopted and never knew where she really came from. Also think they did some thing with the Abbot machine to make her forget and lose her powers. So definitely thinking there is a twist and Veil is actually flea, and her doctor parents knew this and were keeping her safe.
I say Tilda. Mk and Tilda team up and kill all the barons...
Annnd the previews for the next episode show tilda facing off with the Widow. Tilda has never been cut, until now!
The backstory is the Widow saved Tilda but I think Tilda went dark(bajes story shed a little light on this) and the Widow showed up to the aftermath thinking she was saving Tilda. Which would also explain why she knows so much about MK and his powers.
But neither Tilda nor The Widow have been cut if I remember correct? Either way, my money is that Flea is The Widow or Tilda.
The Flea is definitely Minerva. Tilda is said to only be 16, and given that Bajie says that the Flea's disappearance was many years ago, I think Tilda is too young, plus, we know a good bit about her backstory. She doesn't have a lost past like MK, she knows her parents died, and that before being adopted by the Widow, she spent a number of years as a child servant in her home. As for Veil, that's also a no. It was said, verbatim in season 1 (both by Quinn and Veil's parents) that she was adopted by the couple when they could not have their own babies. She was presented to them by Quinn as a gift for their service and loyalty.
Flea is clearly a grown up Minerva. So many hints have been given and we're going to find out when Bajie meets Minerva in the only place he hasn't sought her, the Badlands.
Clue 1: Minerva told Tilda she used to have M.K.'s powers.
2) Minerva is the only one who knows about such power, which is why she was searching for M.K. after he killed the people. She was speaking the truth to Tilda when she said she wanted to help him not become weakened by using the power.
3) Minerva also said that she'd started off as a cog working for Chau's family when she was 13 (a year after she separated from Flea at the age of 12) -- where else does a person wind up when they escape into the Badlands?
4) It would make sense that it happened to flea years ago just as it happened to Sunny/M.K./Bajie when they crossed into the Badlands on the school bus.
5) Then, in Bajie's back story, Bajie nailed it when he described Flea as someone from many years ago -- she'd now be a grown woman like Minerva and not a teenager like Tilda.
6) And also that flea was fighting for cogs even when she was a kid is consistent with her Robin Hood sympathy for the weak and disadvantaged. Minerva is clearly a grown-up Flea from all of the hints given in the show so far.