Mary didn't need to read her daughter's mind to see the gears turning as Nico made plans to upgrade her android army into an undying AI army. In a way that sounded an awful lot like the Arisen, who were more like ghosts in their equipment than living beings at this point, but she wasn't going to dampen Nico's daydreaming by pointing out that her idea was already in use.
Of course, it wasn't quite the same, as the implanted devices made each of them an individual, but in theory a secondary backup could be made and written if the original was destroyed.
Having a more capable command group for the Mecha was a good thing, and being able to reduce casualties to near zero was also a benefit to the entire species, so there wasn't really a good reason to stop her from implementing the plan, only the ethical concerns that she was sure to hear from countless other people.