Twenty wishes is book 5 in the Blossom Street series (published in 2008). The Twenty-first wish is book 5.5 in the Blossom Street series (published in 2011).

Twenty wishes -- Twenty-first wish

"Twenty wishes : At thirty-eight, Anne Marie Roche is childless, a recent widow, alone. She owns a successful bookstore on Seattle's Blossom Street, but despite her accomplishments, she struggles to find happiness. With several of her friends, she makes a list of twenty wishes: things she always wanted to do but never did. When Anne Marie volunteers at a local school, a little girl named Ellen enters her life. It's a relationship that becomes far more involving--and far more important--than Anne Marie had ever imagined. As Ellen helps Anne Marie complete her list, they both learn that wishes can come true...but not necessarily in the way you expect!"-- Publisher.

"The twenty-first wish : Anne Marie and Ellen both wanted to learn to knit. Like many of their wishes, they made this come true, and now they knit practically every day. But Ellen has quietly added a twenty-first wish to her list: that Anne Marie will fall in love with Tim, Ellen's birth father, who has recently entered their lives..."-- Publisher.