It sounded like what her mother (Thea) said about how beautiful Cloud is had a big impact on her
Thea compares Cloud with Sephiroth made her felt like Cloud is something very beautiful, but also out of reach, like a star in the sky, she realized that's why her heart always flutter when she talks to Cloud

And OMG, Tifa is so cute XD
She actually thought about what to do if Cloud ask her out to confess his love to her
She gave it some thought, she knows she likes him, but she doesn't think it's the type of like to want to live a life with him

Tifa was pretty surprise about what Cloud has to say, it was nothing special, he is just the same as all other boys

But that thought did not disappoint her, instead, it made her fell in love

The moment she realized he is not a star in the sky but just a boy right next to her, he became special to her. The type of "like" she would want to live a life with him!!

BRB, I am gonna go cry