Ah yes I knew I'd seen it somewhere before! I saw it in a local shop here today which has a sale on until the 15th (20% off)
The littlelife rein attaches to the top. I'm assuming the harness buddy attaches to the bottom?
I just don't know if the girls would prefer to have a monkey on their back rather than a plain bag.
It would be great to get them to carry their own snacks/elmo/water bottle and so on as 36 hour journey