I hate to say it but they may need different schedules. Or at least until Elijah catches up on sleep a bit more. Would you be able to do that, say with your moms help?
Typically an 11 mo old will need between 2 and 3 hrs sleep depending on the bub. Here's some info
Typical Amounts of Day and Night Sleep. As their A pushes out then their days will get a bit longer but you can keep it in check by capping naps. I do think that Everett is heading to the 2-1.
From 2 to 1 nap transition (10-12m and older). There are basically two options - either long am nap followed by a CN or short am nap with a long pm nap. With these routines, some of the As will be shorter than others. Do they tend to nap better in the morning or afternoon? To keep their bt at around 7 to 7:30 you could try something like this
Wu 6:30
S 10:30 to 11:10. (Cap nap to 40 min)
S 2:00 to 3:30
Bt 7:30
Or
Wu 6:30
S 10:30 to 12:00
S 4:00 to 4:40 (can be capped shorter if they are fighting bt)
Bt 7:30
Wrt SA. Hugs! It's hard. They may also be approaching a WW which may also contribute to some SA. Here's some info on SA
Separation Anxiety. Is Everett clingy during the day or just at bt? You can try WI/WO but I wasn't sure if they were sharing a room (I was assuming that they were). So not sure if this will be problematic for Elijah
Wrt Elijah's sleep. He def has developmental stuff added into the mix. Give him lots of time to practice during the day and in his crib too. At night you may want to try a modified pd. I did this with my ds because he fought sleep (still does
). I would put him down and then rest one hand on his chest and one on his legs. No eye contact. I would hold him until he relaxed and then he would fall asleep.
During his A times, I would make sure he got of exercise so he would sleep well (he only started to sleep well once he was mobile). Also does Elijah have a lovie? I gave my son lovies to cuddle when I removed his paci. I had slept with them before I gave them to him so they had my scent on them. It might be worth a try. Wrt co-sleeping twins, unfortunately I don't have any btdt experience. I know it's done when they are younger. I guess I'd be worried that they would wake each other up rolling into each other. Can their cribs be rolled together so that on one side they just have the slats between them?