I'm guessing...

My brother and SIL have not shared the baby's name so I'm putting here that I think at least one part of it will be Heather. She would be the name sake of their SIL who died when she was 12. I could be totally wrong but my brother said we'd understand why as soon as we heard it. The other option would be some combination of grandmothers' names but I'm betting on Heather.