My biggest worry with another one on the way is the feelings that will assault our 2 year old when baby is brought home. Baby will make both Mom and Dad tired. Baby will need a lot of attention, and worse yet, will distract people from their previously favorite household item, Cora.
We've slowly moved the most important parts of Coras existence to try and lessen the feelings of replacement. The crib changed at thanksgiving, the rooms at about the same time. Now Coras room has all her toys in it, and a bed with sheets she helped Mommy buy. How she handles baby came as part of her Christmas haul. Two different dolls to help her learn to cradle, support the neck, and be gentle with baby. She is infinitely tender, wrapping her up, tucking her in to bed next to her, kissing her softly.
Dad has taken over either bath or books in the evening, so that she doesn't feel that Mommy is rejecting her, when she can't do both in a row. Cora herself picks out cloths and helps mommy put on socks. Her independence will help her cope with a new sibling.
As I grow bigger, we watch a show all about babies being born. Cora talks about where the baby is, in mommy's belly. We tell her that soon, Nanny will come down and stay with her while Dad and i go to the hospital to have her little sister. She nods sagely. She understands. Then she bites the babys ears, crawls into the crib, only wants Mommy in the evenings and insists that every belly contains a baby.
Concept learning, how parents delude themselves into believing that they have prepared their children for a change that will be so fundamental, there is no method besides experience to communicate it.