I'm wondering that too. It could be that she want the AI to understand and mimick what they want to beat and be better at it right away. From the future flashbacks it seems that one of the major goals of the AIs is to understand humans better, whether for infiltration or maybe just to find out what makes their creators tick. I mean, I can't imagine any sentient being who could meet the one who set their evolution (or mechanical evolution) in motion and not be curious. So maybe she just wants to get a headstart.

Another possibility is of course that the machines have factions just like the humans do, and Weaver belongs to some who don't want to annihilate humans make make room for machines in some sort of coexistence. I mean, I guess if the humans weren't completely panicked at the emergence of powerful AIs and tried (too late) to but a stop to them, they wouldn't have dropped nuclear weapons on everything.