Looking forward to more of this high quality story, keep up the good work.

Great work

...Do I even want to know what unbirthing is?

keep up the great work ...

9461949
Not really no.

I am heavily invested in this story. Looking forward to Fluttershy being part of the hive.

I have some reservations on the suggestion of taking Fluttershy. The two of them have already ruled themselves out of caring for the brood because they'd be too busy while maintaining their "pony life" above ground. How is that any different from Fluttershy's situation? It's not like she lays about the house all day. She already takes care of a house full of animals and this would take her away from that leaving those critters in the lurch... and unless some really good excuse can be created, ponies are going to get suspicious quickly when those critters start causing trouble in town.

I'd say of all the girls, Twilight probably has it the easiest and the most free time. Still, the story seems to point towards assimilating all of them and it should get easier to take them in as the hive grows-- mainly because a changeling or two can be spared to maintain each Element's "pony life".

Twilight should also keep that changeling-conversion potion well hidden from everyone, especially Chrysalis. Nightmarish alchemical weapons like that would be all the excuse ponies need to eradicate changelings to the last, and it would be far too tempting to use if it fell into Chrysalis' hooves. Assuming ponies don't try to make a reversal of it to transform changelings.

9343753
Speaking of Changeling Spike, derpibooru 90641, but its not that great. However this one could work, derpibooru 1267689

Unironically the most willing of Twilights friends wuld be Fluttershy. She very maternal and if Twilight explained everything minus the conquering of Ponykind (that comes later) Fluttershy would agree without a doubt. 1) as stated before she is very maternal. 2) she is the element. of Kindness she would be compelled to help Twilight her closest Friend and 3) Fluttershy finds cuteness in everything small and terrrifying alike. On the opposite side of the spectrum Rainbow Dash would be the hardest to convert