If it were not love at first sight, and true love at that, then Ferdinand would have never agreed to marry Miranda and she would have never asked him.  Miranda asks Ferdinand, “My husband then?” (III, ii, 88)  If he did not truly love her, he would not have replied with, “Ay, with a heart as willing as bondage e’er of freedom .  Here’s my hand.” (III, ii, 89)  He gladly accepts her marriage proposal without a doubt in his mind about his love for her.  What more could prove their love for each other is real?
 

The Tempest
Questions
Prospero's Magic
Miranda the Novice
Pimp Ferdinand
The Wedding
Happily Ever After