It is normal in the English language to give nations and ships the female gender.

As we call earth as "mother earth" and "mother nature", which has productive capabilities. Thus we call "countries" as mother lands as they are parts of the same earth. It is obvious that countries are part of earth and we give the earth and nature as feminine status so we call all countries in feminine status.

All languages (that I know) give a gender to objects - masculine, feminine or neuter. In some languages these are very obvious and they require that adjectives are changed to address the gender of each word. English is not so strict in this way but every word has a gender even if it is usually hidden. In this case one's country, or motherland is feminine.