anywhere between 115-130 i think is perfect IMO (waits 4 every1 to attack me awks) but you can weigh all the way up to 149 and still be considered in the healthy weight range..but hun, you look really thin in your picture and i wouldn't consider loosing any more weight! :) xx
Rule of thumb (not absolute) is 5'0" 100lbs +10 max. So at 5'5" you should weight 125-135lbs. That is what I was advised by a doctor.
Your current weight (125) is just about perfect! truly, you do not need to lose an ounce :-)