Need help

My wife just got B1 visa (from this month to August) in Beijing and plan to attend a meeting On March. At the same time, she also received H1 visa (from April, one year) document, but not apply H1 visa yet. My question is that could she come to US with B1 visa , stay here and does not need to go back to Beijing for H1 visa? You know it may have risk to apply H1 visa in Beijing. Thank you very much for your help.