Is the phrase "laugh head over heels" correct ?
You can say she is head over heels without the laugh part which would mean she is totally and completely in love.
A different meaning is 'she laughed her head off' which means she laughed a lot (often loudly)
this phrase is normally used on love affairs.

She is head over heels in over with John.Emotion: smile
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 Woodward's reply was promoted to an answer.
So we could definitely say she is head over heels ---- him. Which prepostition would we use?
"for" him, maybe "about" him, or "in love with" him ... all would be ok
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