All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
You should know that, when we perform Istikhaarah (i.e. the guidance-seeking prayer) and Allaah The Exalted Facilitates the matter or Renders it difficult (and Distances it from us), we cannot be positive that this is the Choice of Allaah The Exalted for us. The Istikhaarah prayer is not a means to know about the unseen or to identify the Choice of Allaah The Exalted for us. Therefore, there is no harm in proposing to this girl again as long as she is religious and well-mannered. If your matter is facilitated, then all praise is due to Allaah The Exalted. Otherwise, you may propose to any other righteous girl. It may possibly even be better for you not to marry this girl.