How to help a friend grieve the loss of a baby?

My best friend just lost her nephew this morning. He was just shy of a month old. He was born premature, but has been otherwise healthy. She's also experienced a miscarriage this past fall. I want to help her and be there for her however I can, but the thing is that I have a 2 month old. I don't want to upset her by my daughter potentially being a reminder of both of these losses.

Originally we were planning on play dates with our children, but she miscarried and we decided on play dates with my daughter and her nephew. I'm just afraid that my daughter will only be a reminder of this and I'll lose my best friend. What can I do to help?