The general idea I get is that the money of the extended family is considered accessible (at least to some extent) by the entire pool. This seems especially true for medical expenses, but also seems true for “investments”.
The boundaries seem really unhealthy to me, but I’m not part of that culture, so I don’t know how it really works (esp. for families with wealth disparities).
One “feel good” story I have heard was when a friend of mine flew from the US to the Philippines with a large sum of cash that paid for a life-saving surgery for grandmother (had to pay in advance).
I’d love to hear other stories.