During the second pregnancy, I was more or less used to the state of pregnancy, the discomfort of having a big belly, the morning sickness and all. They say subsequent pregnancies are unlike first pregnancy, time seems to fly past. I agree, I don't monitor my baby's growth as closely anymore and are more nonchalant about my growing belly. Many baby items can be re-used and it was great on saving money, I actually did not buy any maternity clothes too.
However there are still many things to be done. Top on the list is telling your first born about the incoming arrival of the second child. He or she may not know what is happening yet, but it's good to get them used to the concept of a sibling. Moreover, you will need to transit her to toddler things so that your newborn can use those baby stuff ......