Modify zooper

Question

I am wondering if a zooper i bought for my daughter for one child can be modified to accomodate a second infant? she will have a new baby so that makes two under the age of two! Her zooper is green and i am not sure of the actual name -- it is wonderful but was quite expensive and has not had that much usage, so buying another one is prohibitive at this time. Any suggestions would be great. Thank you -- happy nana.