Monday night, Scarlett co-slept with my SIL because I had a high fever and I couldn't lay still in bed. I tend to thrash when I have a high fever.
I didn't even worry for one second about her being unsafe in SIL's bed and I actually slept better knowing she was being taken care of for me.
If we had to go out of town for a weekend without the baby, SIL would gladly co-sleep with Scarlett for the weekend, and I have no problems with it.
SIL and bro co-slept with all 3 of thier kids, so I guess that calmed any fears I had. Bro opted to sleep in another room because he was afraid he wouldn't co-sleep the same with a child that wasn't his.