In 2018, I wrote a library that extended the LinGO Grammar Matrix to cover adnominal possessive phrases.
The Grammar Matrix is an svn-based project, and the code can be checked out here:
svn co --username guest svn://lemur.ling.washington.edu/shared/matrix/trunk
If you want to try out using the Grammar Matrix, you can visit the matrix customization page.
If you want to read about the adnominal possession library, you can check out my master's thesis (thesis.pdf) or the paper I presented with Emily Bender at HPSG 2018 (hpsg2018.pdf).