Hi Mandy. I have read so many of your stories I can't recall reading this one so if I'm commenting again sorry about that.
This may just be the reaction your brain needs to make to deal with it all. Because it is so shocking and unusually cruel and judgmental. In the future they will be humbled by something that happens in their lives and soften their hearts but hopefully by then those girls are grown up and make their way to you on their own. Right now they are helpless.
How low to do this to you and not explain why. Just to be cruel it sounds to me. I'm glad you have another granddaughter now. Does she see her cousins?