Can my husband's ex wife come back after 10 years being divorced and ask for alimony?

Child support finished ($2800 a month) this year she got a large million $ plus settlement now she sent a lawyers letter demanding $3500 a month (more than I make working 40 hrs!) she states she cannot pay anything toward the now college age kids education or expenses. PS. she was the one that wanted a divorce because my husband's business was going bankrupt I was not in the picture until long after the divorce