Bella wouldn't last 5 mins trying to do any kind of boyfriend stealing of Luke Skywalker! Mara Jade would take her out so fast her head would spin! Callista would own Bella too....
Considering he's in his late twenties to early thirties by the time he marries Mara, I foresee Luke being a little creeped out at a teenager obsessing over him. Their first conversation would probably go something along the lines of:
*waves hand* "you are not interested in me. You want to check yourself into a reputable psychiatric treatment facility and get help for your obvious relationship issues."
And it would work too. Remember, the Force has a strong influence on the weak-minded.
And this is why you don't watch anything produced by Ronald D. Moore after he had his brain surgically removed and replaced with a bag of elephant semen.-Gramzamber, on why Caprica sucks