The hell do you mean by fly weight? Cause I'm pretty sure that the larger girls like Tina mila and Lisa weigh a helluva lot more than say, Marie Rose or the ninjas.
Though if it were being more honest to the characters, Nicole would have completely unlaunchable (like how you ckukdnt grapple The Blob back in Xmen Next Dimensions.)
And that's not even getting into how a living tank like the superhesvyweights should be stem rolling through the lightweights.
I've updated my previous post.
Also, the weight classes in DOA all the way to DOA5U are not arranged according to realism, (in other words they are not arranged according to the characters listed weight). Team Ninja cherry-picked the weight class for each character for the sake of balancing purposes. The only problem is in the end it didn't work out so well. With what Team Ninja tried to do we ended up with some characters being in weight classes that don't make any sense. IMHO for DOA6 they should forget about their own specially created weight classes and instead sort the characters based on realism, (in other words sort the characters according to their listed weight), and following UFC and/or other real world MMA rules:
Atomweight: under 106 lbs (under 48 kg)
Strawweight: 106 lbs to 115 lbs (48 kg to 52 kg)
Flyweight: 116 lbs to 125 lbs (53 kg to 56 kg)
Bantamweight: 126 lbs to 135 lbs (57 kg to 61 kg)
Featherweight: 136 lbs to 145 lbs (62 kg to 66 kg)
Lightweight: 146 lbs to 155 lbs (66 kg to 70 kg)
Welterweight: 156 lbs to 170 lbs (71 kg to 77 kg)
Middleweight: 171 lbs to 185 lbs (78 kg to 84 kg)
Light Heavyweight: 186 lbs to 205 lbs (84 kg to 93 kg)
Heavyweight: 206 lbs to 265 lbs (93 kg to 120 kg)
Super Heavyweight: above 265 lbs (above 120 kg)
If they did that everything would make way more sense, and the weight classes list would look like the list in my previous post.
Oh and:
http://en.wikipedia.org/wiki/Flyweight_(MMA)
EDIT: updated post to include all weight classes that are recognised by the world of MMA.