I have to preface my answer by saying that I have the advantage now of having a 5.5 DD and a 3.5 DD so they can entertain each other well. But, I did have a 2 year old while having a baby and it can be tricky. I would suggest a bin of special toys/books that are only for when you are putting DS down for nap. Or maybe a special assignment (like sorting the laundry to be a big helper) to keep her busy. I personally love the tot-school and preschool ideas on www.1plus1plus1equals1.com. She has lots of things to do with toddlers and preschoolers. I also love the Gymboree books for ideas for what to do with these young ages. Maybe being more intentional when everyone is awake would allow her the space to be a bit more patient when you need to give one on one time. HTH! It does get easier...