The 2.5 year old DD or the 7 week old DS? I've tried explaining to DD that I have to get brother to sleep, and she seems to understand. But what about when it's 9:00 at night and he's still screaming and she's exhausted. She wants bedtime stuff (books, songs, nursing as she drifts off to sleep). Just absolutely cannot physically do it! And I feel terrible about it when she does lie there crying, "I want my mama." DH is at work, by the way. Help!
Somebody has to cry it out?
When mine were that age, I always put baby DD down to sleep before putting DS to bed. Even if this meant that DD would get up again relatively soon, DS still needed me for bed time. He was also 2.5 when DD was born. So I'd nurse DD to sleep at 630-7ish, set her down (wherever she will stay asleep for a little while! Swing? Carseat? bassinet? wherever she will sleep!), and then immediately after put DS to bed. Sometimes DD would sleep through til like 10 (beginning her night sleep), and sometimes she would wake up shortly after DS fell asleep, which was fine. Because once only the baby is still awake, it gets easy. Baby needs to nurse? No need to entertain or appease toddler. Baby needs held? No problem. Plus, baby is more likely to go back to sleep without all of the activity of your older child.
DH is still not part of our bedtime equation, as he is sleeping when they go to sleep, and works midnights. Now that they are older (16 months/3 years 9 months), DD "helps" me tuck her brother in, kisses him goodnight, etc (but he can fall asleep without me now), and then I take DD to bed.
In the early days of having 2 children with this age spread... remember that it's about survival. Do what is best and easiest in the moment to get you through. You don't need to let them CIO, but you also don't need a set sleep schedule, a clean house, or anything else perfect and shiny. Only do what you most to care for them and yourself! Hope this helps!
We had about the same difference in age, and DH was at work at bedtime. We started a routine fairly early, and baby DS fell into it fairly easily. When he was that little, we did his bath, then right after, 2 1/2 year old DD's bath. While she was bathing, I was sitting on the side nursing him in his pj's in the sling. He usually fell asleep. And if it took a while, she didn't care, she loves the bath. After, she was able to do a lot of the work getting her pj's on. Then, we would all get in the bed (we do a family bed) and read books. Usually by the time she was getting sleepy, he was starting to wake up, so I would nurse him on one side while snuggling her on the other. There were a couple of really crap nights where he was up screaming, and then I'll admit that I put the tv on kid stuff for DD and let her "camp out" on the bed. We have a headset for when we watch tv after the LO's are asleep, so she got to use that. It was all very grown up for her, drowned out the noise, and she fell asleep that way. I don't know that it was ideal, but it was the best I could come up with at the time.
Is he up often at 9:00 screaming? Granted, some babies just do, DD was one of them, but if so, maybe that's something to look at? We had about a week of colic before I realized it was oversupply/overactive letdown.
It gets better, though, it really really does! I hope for your sake it gets better soon!