Trailer for Older Child

My hairdresser asked me a question I figured the best place to ask was here! Her daughter is autistic and fairly profound case of autism. I know she is making strides but obviously very far behind where a normal seven year old is. My hairdresser would like to be able to continue towing here in a trailer but obviously her daughter has outgrown the Burley types. Are there any that could handle a larger child? I believe she is the size of an average 6-7 year old. It would be just very short rides around local parks, I think her daughter is not capable of riding a tag along or similar bike. I believe balance would be a major issue plus behavioral struggles.

I will have to ask my uncle. He does triathlons with wheelchair bound children--most of them are 8-13 years old. He obviously has a trailer for the bike leg. I'll shoot him an email.

Just a quick search and I found these:

http://www.caboosetrailerbike.com/

http://www.wicycle.com/special_needs...le_trailer.php

I've been looking at these for for my special needs 3 y/o, in addition to the ones limewave posted:
http://www.weehoobicycletrailer.com/

I also saw one of these on on Craigslist the other day:
http://blueskycyclecarts.com/BSkyHandicap.htm