3 year old waking up newborn

For all you #2+ mommies:

My daughter (now 3) has always been a terrible sleeper. We’ve tried every method including a sleep consultant who refunded us as it seems the methods (including cry it out) were not working. She is extremely healthy and happy during the day. We’ve discussed with the pediatrician and it appears she just doesn’t need a lot of sleep. She’s exceptionally bright and alert and this may be the problem. We kind of accepted that there will be crying at bedtime and we will never sleep through the night until she is a teenager.

The problem is that she is now waking up her 11 week old brother. #2 sleeps OK (gets up twice per night). As we try to get #2 on a reasonable sleep schedule, we can’t have #1 screaming the house down at bedtime every night. We need a new plan. We don’t even care if she sleeps, we just need her to stay in her room quietly and wind herself down. Any suggestions? (Obviously no TV)