Countries being called she/her

Some are also called he/him. Germany is called the Fatherland. It's maternal/paternal, a large, encompassing, protective figure. We do it to ships as well.

Countries used to be represented in art by personifications, a human figure that allegorically represented traits the country was known for, for example the United States was portrayed as Lady Liberty, the United Kingdom as Britannia, France as Marianne, etc. For some reason, these personifications were always women, and the practice of referring to the personification as 'she' extended to the country itself.

I've never noticed that with countries. I have heard she used with ships though.

There’s a very famous poem about my country which uses ‘she’ and ‘her’ — we see it as a poetic device and not something we’d use in everyday speech.

As I know only if a noun has a distinctive name (people name, pet name or etc.), you can use her/his but if it's a noun has no gender you have to use "its"

we personify things sometimes. i call machines she.

This isn't limited to English; humans gender a lot of non-human objects or beings. Objects like ships, cars, etc. Beings like animals (calling pets "boy"/"girl"), aliens, robots, etc. The reasons vary a lot depending on what the thing is, but it is likely an extension of personification, which is the assigning of human characteristics to non-human things. One of those characteristics is gender (different from sex, since gender is social, not biological).

This is a form of Poetic Anthropomorphism. It's not so much a grammatical thing as it is a literary thing where the speaker builds a more human connection with a non-human object or concept by ascribing human features to that object or concept (in this case, a country). It's not an aspect of standard speech, but it is something people will add as a poetic flair even outside of actual poetry. I suspect that some aspects of this practice have their roots in English being a Germanic language and Proto-Germanic most likely being a fairly heavily gendered language. However, I haven't read up on the research of that.

It's very old-fashioned but the country is treated as the metaphorical mother of her people. I wouldn't even think about doing this, it's not even that common and fairly pretentious.

This comes from cultural feelings and the olden days when English still had declarative gender. Ex “the(feminine) house” or (the(masculine) part” etc. etc. This was lost with time and the original sayings likely didn’t change with it. That and countries being animate gives the phrase some cultural feeling. As the country is a personified thing that lives and breathes.

it's not grammatical. it's potentially controversial with some audiences, who see it as part of a larger trend of not treating women as fully people.

It's poetic, but it's fully optional.

Some people do this for ships countries and cars. I don't do it for anything.