What is the familial convention for Puerto Ricans?
I'm not quite sure what information you are seeking. Even so, since this is not my area of expertise, I searched Google under the key words "'Puerto Rico' familial relations" to get these possible sources:
http://www.everyculture.com/No-Sa/Puerto-Rico.html
http://saxakali.com/caribbean/YeseniaE.htm
(Broken Link Removed)
http://gas.sagepub.com/cgi/content/abstract/17/5/664
http://books.google.com/books?id=ROuqj_xIRMoC&pg=PA134&lpg=PA134&dq=%22puerto+rico%22+familial+relations&source=web&ots=L3cj6XTNWt&sig=T4jp4-I0UYTenfCLWTMAqwXkROA&hl=en#PPA134,M1
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.