Hmm...very interesting story. Any chance perhaps either Lily is in fact Lili Fini Zanuck? She and Richard were the producers of the recent Academy Awards show.
Lili's also directed country/pop singer Faith Hill's "Breathe" video, and co-produced "Driving Miss Daisy" and "Cocoon", and some other recognizable Hollywood works.
What's confusing here is that the bio at the link below seems to indicate she was born in Massachusetts, raised in Europe, and she and Richard were married around 1977, and appear to still be married - but you say your Lily has remarried.
Could it be a coincidence that Richard is associated with not two, but three Lil(i)ys, possibly two by marriage, and a daughter from one of them? Seems like long odds, but not necessarily impossible...would be quite neat if Lili was a member of the extended family, though.