Nina watched as her puppet walked with confidence through the soul fire that she had ignited. She had essentially stolen those souls and they were vengeful. But it was reasonable for them to be.
First she stole them from living beings in realms from the siblings domains then she stitched them to the torn soles of her created offspring. They ended up living a half undead life which was an abomination in the order of nature. This caused both souls to be in indescribable pain.
Bottom line. Nina did not want vengeful souls taking advantage of a moment of distraction while she fought the siblings.
Her puppet on the other hand was created some time ago. She knew that everything was now destroyed and they had to move to a new plan but she did not fully understand the true problems that they were facing.
Nina did not give her that much information.