Thanks for the question. Assessments of the children could be integrated into the pre-and post pilot assessments already built into the project, using the Bayley Scales of Infant Development (or an equivalent test). The participants could also be asked for their subjective assessments. Ultimately, it would be nice to follow up after longer time intervals and add a control group.
Thanks for flagging that. The idea is meant to be easily used in any setting, and is partly inspired by games I've developed and used with American teenagers and adults. Two specific (although not necessarily unique) considerations for U.S. participants, which a pilot could help us explore, are the best ways to fit the sessions into participants' existing commitments, and branding or presentation that would be sensitive to potential stigma around roleplaying.