Sarah,
*L* I seem to find you everywhere!
OK, if the goal you want is different than the goal they will let you have, all you have to do is get a form and get your doctor to sign it. Then, your goal can be whatever you want. (Within healthy reason, which 141 is!)
Next, as long as you are within the weight range for your height and weight, they cannot do anything! If you go below the minimum recommended weight you will once again have to get a letter signed by a doctor!
My goal was 148 and I was down to 137 for awhile and the various weighers and leaders had no problem with that. Man, I can't wait to get there again!

Hope this helps!
Tara