What should my bridesmaid wear if it's chilly?

I am getting married outdoors the last weekend in April. In case of chilly weather my bridesmaid asked me what she could wear with her dress. I don't think a little shaw would cut it. And she hasn't gotten a dress yet, but my color is tan/neutral/or very light brown. I don't really want one of those "matching jackets" that come with some dresses, but I feel like I have no other choice! Any suggestions?