BU (and Boston) has a strong Jewish community, but in my opinion, the state school is the obvious choice here.
Don’t feel bad about having applied ED2, and then declining for financial reasons. BU has banner ads all over the internet about “merit scholarships for test-optional applicants” which imply that there’s plenty of merit money awarded - I don’t believe that is the case. I think that they’re just trying to goose their application numbers. If she really wants to go there, contact the admissions office and ask for more financial aid. Explain to them that your family’s economic circumstances mean you will have trouble with what they’re expecting you to pay, and that you will be forced to decline for financial reasons if they cannot improve the deal. And if they cannot, I’m sure she’ll do very well at the state school, too.
Don’t feel guilty about having applied ED2 and then realizing that you couldn’t swing it financially. You didn’t set the rules of the application process, and surely you aren’t the only family that would have realized that they cannot pay the price asked, after having received the acceptance letter.