What the last two suggested are very good. I would also ask your little girl if she wants to help you take care of the new baby. Basically tell her that it would be her baby too. She would have to understand that she could not do anything with the baby unless you were with her of course. That way it gives her a little responsibility which she will love. Plus it won't take away from her 'mommy time' either. It will be a wonderful experience you can share together.
Maybe after the baby is born and you wipe the baby down with whatever you will use, you can guide her hand and do it together. When you feed the new baby, you can teach her to stroke the baby's head or arm. She will feel just as needed and loved as the new baby and feel that she is a part of everything. Sometimes older children can feel as if they are left out with the new baby. The trick is to involve her. I have a step daughter that had 3 children in 4 years. The older ones always felt left out and caused problems because she didn't involve them in helping with the baby.
My little girl is 5 and when I had to take care of her younger children who are younger than my daugther, I taught her to help me with them and there was never any jealousy which was great.
Good luck with the new baby and congratulations!!!
E.