But tjj said she was travelling in July. The setting sun would have been in (broadly ;)) the NW. That could not possibly work Alken.
When you say 'facing the sunset', do you mean the body of the horse facing the sunset or the head pointing toward the sunset?
If we're going with the 'galloping' thing, you surely mean the head 'toward' the sunset, which as the sun was in the NW is absolutely wrong in every possible way.