Could you, please, help me with this sentence. If I were to say such a sentence should I say "a half of the first floor"?

"She's been mopping for hours and only finished maybe 1/2 of 1st floor".

Is it correct to say:

"She's beem mopping for hours, but she hasn't reached a halfway"?

Thank you
Not really. Use this:

She's been mopping for hours, but she's only finished half of the first floor.
Thank you, Mister Micawber Emotion: smile