Relatives appear in O Grande Almanaque Disney #19, released this month Source:https://www.facebook.com/culturamaeditora/posts/pfbid02YjNoUgw3VV3XyXPPeLRPaKEDnex8R7w8ATVTWGHeMTeKkYVi3UqMpPzLRRxs2Tenl
The grandmother is called Isaura, I don't know if she's the same Grandma Carioca from the Dutch stories, there's uncle Plínio and another one who seems to be an aunt, whose name is not mentioned. Source: www.youtube.com/watch?v=jJ7aZQ_XfGI