I've received lots of emails and comments about this post from people looking for a way to put all three of their kids in a bike trailer. I updated this post with more information about the sling I use.
So one of the things that I was most worried about when Juno first went into her Spica was the stroller situation. Luckily, the bike trailer that my wonderful in-laws gave me for my birthday 3 years ago has been a lifesaver! Helena was just a little baby when I got it, but I remembered seeing someone in Laramie with some kind of infant sling in their bike trailer at a park. So I logged onto the Laramie FreeCycle page and asked if anyone knew what they were called or where I could get one. Much to my surprise, I received one in the mail just a few weeks later--for free! Isn't that amazing that someone would send a total stranger something so expensive that they could have resold?
Anyway, it is perfect for Juno's cast. I originally had it in a side position, but her legs stuck out too wide and bumped into the side of the trailer, so I moved her to the middle. And even better, Tempe and Helena fit in the trailer with her! Going for walks hasn't been this pleasant in such a long time. I can actually walk at a normal pace instead of taking three steps and then turning around and saying "Come on! Keep walking!!" over and over.
Some more info on the bike trailer sling: My bike trailer is a Copilot (it has a picture of a kangaroo on it). The sling is made by Chariot and is designed for use in Chariot trailers. Here's one on Amazon. My bike trailer isn't compatible with the Chariot sling, but I just cut a slit in the fabric at the bottom for the sling straps to go through and wrap around the bottom bar. It was very easy to figure out how to get it to work in mine--I'm not familiar with other brands of bike trailers, so I have no idea how easy it would be to use a Chariot sling in other trailers.
Disclaimer: The Chariot infant sling is meant to be used in Chariot bike trailers that are being used as strollers; it is NOT meant to be used with an infant when the trailer is being towed by a bike. It is also NOT meant to be used three across in a trailer. My trailer only has two seatbelts, so my older girls were not strapped in when I had all three of them in the trailer. I DID NOT use it as a bike trailer in this function, only as a stroller. Use at your own risk!!