I have an assumption that the Absolute is just a proxy of Lolth who plays with tadpoles, they are one and the same. The following things speak in favor of this:
1.) Goblins do not attack drow because "the drow bears the seal of the absolute." Lolth believes she has rights over all drow.
2.) Minthara talks about returning to Menzoberranzan under the control of Lolth's clerics, as if she would be greeted there with honors and not executed for not serving Lolth.
3.) Betrayal of a character who helps the Absolute is pointless, but it's very Lolth's style to give such an order.
4.) Minthara mentions "test of the absolute" - "test" is a typical mechanic for Lolth, other gods have not been seen in such perversions (https://www.realmshelps.net/charbuild/races/elf/drow2.shtml
5.) Minthara gives us Drider to help us as if she were actually a cleric of Lolth
6.) She has a Lolth tattoo on her neck (is that a Lolth cult tattoo?)
7.) From the slain drow worshipers of Lolth, a small spider crawls out, very much like a tadpole.
8.) Her eyes is red
I would not like this, but other players' guesses are interesting. It is also obvious that the Shar also has something to do with this.
Perhaps she served another god of the Dark Seldarine before?
Or did Lolth serve, but disown her in favor of the Absolute?
That is, Minthara does not know about the tadpole, nor about the role of Lolth, and may be very surprised in the future.
This raises a number of unanswered questions. What are your assumptions about the relationship between Minthara and Lolth?