I think Northern Virginia is a wonderful place to live. You have all the cultural resources of DC (with tons of free museums and events), a diverse population, decent weather with seasonality, other metros nearby—the list goes on and on. Like any area it has its downsides (high COL probably chief among them), but this area has unique attributes that make it special. As for schools, Arlington may be a good area to focus—there is more of a walkable community feel to its schools and neighborhoods than many places in Fairfax, and you’ll be closer to DC to take advantage of what it has to offer. Falls Church City is also an option—it has its own small school district which makes it unique in the area, and that has both advantages and disadvantages. The downside is housing costs close-in are higher and houses tend to be smaller, so that’s a trade off.

Arlington has a public Montessori elementary school, which might be of interest. I don't know what the process is to get in if you aren't applying through the kindergarten process.
https://montessori.apsva.us/

In Arlington, with your budget, you'd be looking in South Arlington and townhomes.

Hi OP! I’m a gay mom, used to live in dc, now live in the Chicago suburbs. If you’re going to live in the area, Maryland may give more of what you want - but just wanted to echo the others that another city might be better! I’d pick somewhere that is not Florida and an easy drive/train/flight instead.

Is being near other Brazilians a draw for you? I would recommend focusing on those areas if so.

Honestly if you don’t have to live in the DMV I wouldn’t. It’s not a great place to live with the new administration and it’s just overall kind of depressing. I used to love living in DC (and this was after living in New York for many years) and now I just want to leave but both of our jobs are here.

In 1-2 years that budget will likely have to go up to buy.

Falls Church City checks a lot of your boxes and you could arrange a tour there by contacting the elementary school front office. 3rd to 5th grade is Oak Street Elementary.