Is it permissible to speak with a girl via social media to find out the result of Salat al-Istikhara regarding marriage to her, knowing that she lives in another country? And if it is not permissible, what is the correct course of action?

The result of Istikhara is known by the success or lack thereof in the matter for which Istikhara was performed. It is a delegation of the matter to God, so that He may choose what is best for His servant. It is advised not to proceed with marriage to a girl known only through social media. Rather, her situation should be ascertained by people who know her closely, so they can describe her religiosity and character, in order to determine her suitability.