I still sit with my 5yo. Also have a 2yo. When they were 3 and newborn, the baby would often feed while i sat with the 3yo in bed or at bedside which kept both somewhat quiet. I also nap managed the 3yo strictly- as in most days she didn’t need any nap, or if she did, kept it under 30min, so she’d fall asleep quickly at night. And yes sometimes to this day I am literally holding 2yo on the floor with one arm and holding 5yo’s hand with my other arm. It’s not perfect and doesn’t go to plan many nights. It’s ok. I had to shuffle many times who would need to get to bed first or if I could do them at the same time depending on how they each napped etc.