Well, Im no expert, but in the movies they always film low angles to make people look taller and film people at diff depth to make people look closer in height. For example War of the worlds with Tom Cruie and .......I forgot the other guys name, but one guy is like 5'7" and the other is like 6' 3". OK..........it's a wedding not a movie. I guess you could
1. have her in the foreground and him backgound 1-2' back. Play with the DOF to get the right look.
2. You could have them lying down.
3. he could pick her up (although this might look like dad holding a little kd).
4. You can have them stand on diff steps and just use close ups.
5. You could have her looking up into his eyes, from the side.
Just helping you brainstorm, no expert here