We kept co-sleeping with a new baby.
For the first few months DH slept in one bed with the toddler (16 months old when the baby arrived) while I slept in the other bed with the newborn.
When DS2 wasn't so newborn any more and DH was away I would sleep between them.
Once DS2 was a toddler they slept together in a double bed. Now they have bunks but most nights they choose to sleep in the same bunk head to toe athough we still play musical beds. DS2 comes in with me most nights at the moment because DH is working away and DS pops in for snuggles in the morning between waking up and getting up.


If you have 7 months you can use the time to get your DS more used to sleeping with your DH.

I don't think it would be safe having a baby and a toddler side by side without an adult between them. I think that 4 in a bed is just too many to be comfy - we've got a king sized bed and 4 is great for snuggles but a proper nights sleep is impossible when it's that crowded.