Your friend will need to have her first marriage looked at for validity or nullity before she can marry in the Catholic Church. Civil divorce does not end a valid marriage so if it is determined that her marriage was valid when contracted, then it is still valid and she is not free to marry at all. If it is determined that her marriage was not valid (was null) when contracted, then she should be free to marry. In such a case, her Catholic boyfriend will need to obtain permission (if she is a baptized Christian) or a dispensation (if she is not baptized) to marry her, a non-Catholic, and he will be required to make certain promises. Then they should be able to have a Catholic wedding.
Catholics take Jesus’ teaching very seriously: “What therefore God has joined together, let no man put asunder” (Mt 19:6).