Can I get rid of red letter pluralization that automatically populates new pages

"Yakimas" seems to see some usage, however. [1] There are some usages in that selection of "Yakima" as the plural of "Yakima" too.

If you want to specify that it has two plural forms like antelope, you can use {{en-noun|pl=antelope|pl2=antelopes}}. For more sophisticated things, you could use, for example, {{en-noun|pl='''moose''', (''chiefly humorous'') '''[[meese]]''', (''dated, rare'') '''[[mooses]]'''}}.

Hope this helps.

She was Yakima. She was one of the Yakimas. She was of the Yakima. She was of the Yakimas. Yes two plural forms.