supportive of one "and" another

[sitifan]

Everyone is so supportive of one and another and I am proud to be a member of the group.
https://tomorrowswomentoday.com/member-profile-katie-crawford/

In the quoted sentence, is the conjunction "and" obligatory, optional, or redundant?

 

[GoesStation]

It's not just redundant, it's wrong. It's an editing error,