Any suggestions (infant death mentioned)

I'm going up to my nephew's funeral tomorrow, and next week my sister's
coming back to stay with me. I'm having to take #2, and I'm scared of saying
anything tactless or insensitive. My thoughts at the moment a
I have a small (cherished teddy) ornament to give them and a card, and Mum's
getting a pot of tulips for me to give (I'm going up by train so I don't
think I can carry it) so they can choose to plant them later if they wish
to.
All the clothes I'm taking for #2 will be girlie and not babyish so she will
be less of a reminder. She's also meant to be sleeping in his cot (their
suggestion, if it's a problem then she'll cosleep with me) so I'm taking a
pink blanket.
I have done a little booklet for the children, about Matthew so they don't
forget him. I would like to show/give one to my sister at some point? I
thought probably not at the funeral, any suggestions when?
I am going to do a little diary of the messages mum sent about Matthew, and
things that are to do with his life, plus recording the "goodwill messages"
we've got. I thought that later she might like to look at it and see other
memories of him.
We also have 3 pictures of him on the computer. I will offer to cut a CD
with them on when she's here.

Any suggestions other than the obvious: i.e. not complaining about the
children(-or saying how wonderful they are!!) not making stupid comments
like "all for the best, or you'll have another". Anything that people could
say was particularly helpful-or unhelpful to avoid.
Debbie