Question about pronouns

This is a pretty niche question, I guess, but it’s been confusing me for a bit- I try to get a lot of Russian reading input in, and sometimes I see the pronoun (?) “ею”. I never learned how to use this, and I can’t find any conjugation table that includes it. Could somebody clarify this for me, please? Thank you!.

This is a slightly outdated form of ей. It is often used in literary works, or in poems or songs because of the rhythm, as it does not have one syllable like ей, but two.

thank you so much!! that makes a lot of sense and makes me less worried that I’d somehow missed some essential part of Russian grammar.