I love it that @anahilarski posts in Spanish even though my reading ability is not very good.
It makes the most sense to post in the language of your audience, yes? If you want your audience to be mostly Spanish and you are fluent in it like Ana, then post in Spanish.
If you want your audience to be English even if you are not a native English speaker, you are better off posting in English, right? I love how you two work as a team too. One of you covers the Spanish market, and the other the English one!
I don't mind the posts in other languages, but I honestly do not look at them much. The only ones I do look at are Spanish, and that's because I'm currently learning it as a second language.
I always bet on my strengths and Ana definitely feels more comfortable writing in Spanish.
Makes sense! (Putting your effort into your natural talents and passions). ;-)