Re-applying for visitor visa ..

Hi, My mother visa ejected twice in 2001 which years back, I have scheduled her visa interview again in July. My question here is, should I write a letter to convince the ambassy that my mother is returning back (as mentioned in letter format re-applying for vistor visa) or is it okay to prepare a fresh letter to ambassay as if she is appearing for the first time. Quick response is highly appreciated. Thanks.

They would know about the past rejections and can question about it. So your letter should say something like you want to invite her to US for visit blah blah … she will stay here for xx weeks and plan to return to her home country after that as she has zzzzz responsiblities there etc etc.