The characters straddle the fine line between being wholesome role models while still feeling real enough that kids will identify with them. The only bummer for kids who don't know Portuguese or Spanish is that the series isn't available dubbed in English, so the subtitle reading could turn away some potential fans. Personally I find the show to be very refreshing and Portuguese is such a beautiful language.
Parents need to know that Mila in the Multiverse is a sci-fi series where characters travel between multiple universes. There's a fair amount of scariness and violence -- the evil Operator characters are pretty foreboding, and frequently make threats on the characters' lives. While the content is great for tweens, viewers who don't know Portuguese or Spanish will need to read subtitles of the dialogue; the amount of reading may make it more suitable for slightly older kids.
It's so good!