as for leaving them in the same room (eg to go to loo), my advice is put the bub in a bouncer in the middle of the playpen. I used the capsule, but same thing. Also, from day one, if Chantelle is going to touch the bubs, simple things like repeating gentle and guiding her hand. I found Kat very good like that. At feed times, I'd put on one of Kat's fave DVD's to distract her a bit and she'd sit the opposite side to that I was feeding on. It worked well. She will get jelous, she will want to be as close to you as the new bub, hence the reason I sat her on the other side of me so she could snuggle into me still....
I hope someone from ur fam can help a little for the first few weeks untill you get a routine going. I found once I had a routine, things went smoother and once in a while I'd get the kids down together and be able to nap too.....
Any way I can help I am happy to!