Does anyone have suggestions?

Two years ago I was a 150 lbs (I'm 5"4') I really didnt like the way I looked so I decided to start eating better. At the end of March this year I came accross this website and fell in love with it, Calorie Count helped me get to my weight goal (110 lbs). :) The thing with me is my stomac does not seem to get flat, no matter what I do. At one point it was flat (June this year - 102 lbs) but I was really underweight and the rest of my body looked too skinny and discusting really. So I decided to put on some weight again, I am now 115lbs and I feel great and I love the way my body looks except for my stomach. It seems to me that the 13 lbs that I have put on purpose all went straight to my stomach. I am not sure if this makes any sense but would any body have any sugestions on how I could firm up that stuburn stomach of mine without losing too much weight, I don't want to be underweight again.

Thanks in advance!

I also forgot to mention that I am a female.

Well... are you exercising? 

If you aren't, do. And don't concentrate on ab exercises - weight lift and do cardio as well. 

If you are, then just be patient. Sometimes people get very unlucky and the last bit of fat takes a long time to go away; longer, it seems, when it's someplace you don't want it to be...like your tummy.

http://www.metacafe.com/watch/925256/how_to_g et_six_pack_abs_in_6_minutes_on_your_couch_th is_works/

Abs are made in the kitchen. 

No amount of situps, crunches or any other 6-minute miracle exercise is going to get your ripped abs OR a flat stomache. 

There are a million posts in the fitness section about this.  If you do want to make your "core" stronger, deadlifts, squats, planks, etc.  will help.  Also you can strengthen the rest of your body which makes your stomache/waist look smaller and more in proportion.