Dear Sir/Madam,
I am sad to say, but we currently have no cart or cargo bike that would prove suitable for this occasion. We do have, however, a tandem bicycle at our disposal, so as far as past experiences go, this may be a reliable alternative.
As tandems usually have synchronized pedals, I would like to explore the remote possibility of removing the second set of pedals and installing a place for a more comfortable foot placement that does not involve movement. A more likely scenario, which depends on the injury may involve keeping the pedals, in which case your daughter would only have to mimic the movement, but not exert any force.
In any case, I hope your daughter will get better soon.
All the best,
Jack
Waypoint Tallinn