Need your advice

My two brothers and I are U.S. citizens. My father passed away six years ago. My mother applied visa 5 years ago and last year too. All rejected. One of my brother went back to China to work this year in my hometown. Do you think my mother can get her b2 visa now because she has one son in China (he is a U.S. citizen and going to work in China for three years - three years contract).Does that mean she has chinese ties? Thanks.