Hi Tiff -
I can't imagine how you do it!!!! My DS is a non-sleeper but I only have him to worry about. I applaude you for managing everything that you do! I don't have any advice that hasn't been offered - though I did see something in a different post about putting epsom salt in the bath to help calm them, which I am considering trying with DS, but I can't remember where I saw it - sorry!!
I was wondering how long Ivy slept when you finally got her to sleep this arvo. My DS is down to one nap a day and it is usually about an hour and a quarter which seems like an eternity after reading that Ivy only sleeps 20 minutes!
Good luck getting some sleep tonight and please keep us all posted - I too - am curious to hear what you find out from the sleep study. Hang in there and know that we are all here to help - even if it is only to listen.