How are the Gummi Bears related to each other

Question

I recently rewatched Disney's Adventures of the Gummi Bears. The general opinion is that they are not related to each other. There is no father/mother/daughter/son scheme.
^{Only Sunni and Cubbi are siblings}

Question: Is there any evidence for relations between Gruffi, Grammi, Zummi, Sunni, Cubbi and Tummi

I'm constantly asking myself

• Are Grammi and Gruffi the parents or grand parents of the three younger bears? They act like grnad parents but it is never clearly mentioned. "Grammi" could be short for Grandmother
• What is Zummi? A brother of Grammi and Gruffi?
• What is Tummi? A cousin? He's never called brother
• How did the kids get to Gummi Glen without their parents? Where are they?

Should I assume they left there kids back when sailing across the sea? How cruel is that?

There are 95 segments (1 or 2 per episode). Maybe I'm missing something or there are books, comics to complement the TV series

Answer 1

We simply never get any information throughout this TV series about family relations between the gummi bears of Gummi Glen or facts about other relatives. But some breadcrumbs can be combined concerning time line:

Nearly all gummi bears were displaced across the sea by the humans beeing jealous of their advanced knowledge, and only a few remained to call the others when it is safe to come home again (mentioned in "Light makes right"). These gummi bears hide from people, therefore no human beeing have seen a gummi bear for about 500 years (mentioned in "The magnificent seven gummies"). That this period can be devided by 100 is confirmed by the appearance of Gummadoon, a great gummi city hidden by magic which only appears every 100 years for one single day (mentioned in "The knights of Gummadoon").

Over the centuries the number of remaining gummies decreased and most of their former settlements are nowadays abondoned (mentioned in "Up, up, and away" and "Day of the Beevilweevils"). And the six protagonists of this series are the last descendants of the gummis of Gummi Glen.

But we never get to know, how old they are or even what is a normal life expectancy of a gummi bear! Therefore we can not estimate, how many generations of gummis have lived in Gummi Glen since the gummi's exodus.

The sequence of the gummis concerning age is easy to guess for the younger ones but tricky for the adults. Zummi and Grammi were favorite schoolmates and therefore may be nearly of the same age (mentioned in ""Little Bears Lost"). When Grammi went to school, Gruffi was a baby and Tummi was not even born (mentioned in "Gummies Just Want To Have Fun").

German viewers may think that Grammi and Gruffi are a couple, but this misbelief is based on a mistake in the German synchronization: One time Grammi quarreled with Gruffi and said to him angrily "I'm goin'" to point out, that she is not of his opinion and will go with the other gummis (in "Zummi makes it hot"). But in the German version, this very sentence is translated with "Ich verlasse Dich", which means "I leave you!".

Answer 2

It was never established. They live like a family but their relation never got stated. It only indicates that they are sole survivor of Gummi Bears race and live together hiding from humans. And as story progresses it never looked important either.