I started putting both to sleep in the one bed. I always do bed time alone, so I do bath then stories all together in my bed, then I lie down between the kids and boob ds while dd cuddles my back. It changed my stress levels hugely at bed time. You could then transfer dd to her own bed if you wanted, but I ended up just doing a family bed.

You have to time the nap times etc so both are tired at the same time, but IMO getting them to bed together was so much less work than entertaining one while getting baby to sleep then sitting for ages while other falls asleep. I cut the settling time in half by combining it.

Now if dd wants to stay up longer with Dh she can but that's only recent and only on the rare nights Dh is home (weekends mainly)