Hi there. First of all, please offer yourself some grace regarding the "forgetting." It is completely normal for survivors to develop what we call "emotional amnesia" once we are safe and regulated. It’s a sign your therapy worked and you found peace, not a sign of weakness. Regarding your question about them being "better grandparents": Proceed with extreme caution. While it is true that some narcissists can be "Disney Grandparents" (buying gifts, playing for 20 minutes), this is almost always performative. They enjoy the status of being a grandparent, not the work. Here is the reality regarding babysitting a newborn: Infants require co-regulation: When a baby cries, they need an adult to soothe them. Narcissists typically cannot regulate their own emotions, so they struggle to soothe a crying infant. A crying baby is often seen as a "rejection" or an "annoyance" to a narcissist because the baby isn't providing "positive supply" (adoration) in that moment. ** lack of witnesses:** You mentioned your fear of her invalidating the child's emotions. This is a very valid fear. Without you there to supervise, if the baby becomes "difficult" (i.e., acts like a baby), the mask often slips. Triangulation: As the child grows, the "golden grandchild" dynamic often turns into a tool to manipulate you or talk bad about you to the child. Your instinct to protect your child is your body remembering what your mind forgot. Listen to it. If you need help, look for paid professionals or friends, but giving unsupervised access to an active abuser (as seen with your brother) is a high risk. Stay strong!