Some context for this line...
In the Loveless editor she says it right after Cloud's line “Ugh…what are you making me do?†and before his line "...Aeris" (which he says as she falls into his arms), so it would be the last thing said by anyone before she died, and would have been said after Cloud had come to his senses.
I think the scene works better with her not saying anything. Her silence here adds a certain purity (and possibly innocence) to her character, and the juxtaposition of this characterisation of Aeris with the tragic and shocking nature of what happens straight afterwards intensifies the impact of the latter.
