Why would a woman/girl call a guy “hers/he’s mine?

I love my dear friend. A very lot so much so I’d love a fiuture with her, though we are friends now. But one eventful day spent with another female friend subconsciously my close friend and I spent with this young lady and by the end of it I very much had already and reaffirmed “yup I’m hers” though not audibly but it could be felt I’d assume. But seems like she said, “He’s Mine.”

all in all I need a lady or two to help me with what that means from a woman

P. S we are close, I’d spare time money energy for this lady and consider her very beautiful inside and out inspite of her flaws.
lastly THANK y'all SOOO MUCH 🙂😊

Updates
7 mo
For sake of clarification these statement “I’m hers”- - “He’s mine” were not spoken directly more so subconsciously towards the female friend. Probably overshared really want to know what “He’s Mine” could mean coming from a girl/woman
Updates
7 mo
I will add this not to ruin the purpose of this as being a Discussion but simply that my aim was to know why a woman would say or mention a guy as hers.

On that note thank you all for the comments and questions the little opinions and opportunities to share more with you all,
Sincerely,
AGreatManBro
Why would a woman/girl call a guy “hers/he’s mine?
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