Half the battle for applicants is to be interesting, and being a twin is interesting. Many twins end up going to college together. It’s not surprising, and there’s nothing wrong with it. Our twins will not be going to school together because their goals are different enough that fit led them to different choices - though half the scools they applied to were common to both. They had already decided they would not room together under any circumstance to ensure their continued independent development.
Unlike OP and her twin, mine were not looking at the most selective schools - and we never considered trying to somehow tie the applications together (or avoid doing so). In OPs case, their background is somewhat unique, which certainly won’t hurt. I don’t see how being Hispanic wouldn’t help, regardless of SES. Since the sister’s early record was affected by “personal difficulties”, she may very well have potential on par with OP.
Since the top schools are reaches for almost everyone, I do agree with others who suggest compiling lists that make sense for each twin, although I suspect there are many schools that would do well for either.