In this GDC presentation Irrational Games' Shawn Robertson explains how nothing worked first time and, at one point, the studio had a 13-strong 'Liz Squad' who's only job was to “give Elizabeth life”.
You'll have to click through the link below to watch the presentation as there's no embed-able video but its worth it. The amount of time and effort that went into finding and then solving the problems of creating a believable human character are fascinating. From the dress to the 'Booker, catch!' mechanic everything involved a huge amount of trial, error, resources and work. You have to wonder how much of the delay was tied into bringing Liz successfully to life.
Creating Bioshock Infinite's Elizabeth [GDCVault.com]