Ang,
When my grandfather died in 2002, I took my 4 children to the funeral and the burial (I only had 4 at that stage).Lizzie was 4 mths, Tim was 23 mths, Kate was 3 and Jack was 6, they were all very close to their grandfather and they all had a special job to do and that was to comfort us.
I found that the funeral was boring for them because they couldn't move around, but my dad thankfully took the youngest two outside so that I could concentrate.
We had organized with the priest that they had a special part at the burial. What they did was, they played the Collingwood theme song one last time for him and sang with it so he could hear them. It dosen't seem much but it had us all in tears and I found that it helped us express our grief.

Hope that helps, try to see if there is anything that Gabby can do as her special part in the ceremony.