How to get the achievement mother knows best?

[Cptn Teeto]

Anyone knows? Must I not get any clues?

[arronax06]

You can do whatever you want, as long as you don't displease Cetana when you talk to her (so you need to agree to whatever she asks for), or attack her ships before the game tells you that you can do it undetected :) . Once you get enough clues, you can declare war on her once you know you can defeat her, and you'll get the achievement :)

[arronax06]

Ah, and something that is easy to mess up: hacking the data cache she makes you dig up will void the achievement, even if she doesn't realize you did it.

[Cptn Teeto]

Thanks a lot! I messed it up with the data cache then.

[bjamminloe]

So this makes no sense. The achievement is "do everything she asks". So I did. I never attacked a single convoy, nor her outposts. Diplomacy showed I was unable to declare war on her. Then suddenly she declares war on me, and her 700,000k colossus, coupled with several 200k+ doom stacks annihilated my fleets (I was over 3x my ship limit). Then she steamrolled my 25 worlds, and game over.
Seems there should be a "we go willingly into the dark" option for this; there is a different achievement to defeat her.

*edit*
So I restarted Stellaris today to again try to get this achievement, and it popped up as soon as the game front screen appeared. I guess doing everything Cetana wants, include letting her annihilate you, gets you the achievement.