I've got peace like a river
I've got peace like a river
I've got peace like a river
In my soul (repeat)

I've got joy like a fountain...
I've got strength like a mountain...
I've got hope like a rainbow...
I've got love like an ocean...
I've got peace like a river...


On the other hand, since it is a vigil, there's nothing like We Shall Overcome-


On another hand, since it's for the children, you might consider the Russian song:
May there always be sunshine
May there always be blue skies
May there always be Mama,
May there always be me.

Blessings on your event, and may the children of Iraq cease their suffering soon.