Hi Lynda,
Congratulations on working out for 2 months!!
What you may be experiencing is just the fat over your belly and not that your actual lower ab muscles are not firm. What happens is that you can't spot reduce the fat. Only a combination of diet and exercise can make that fat go away and unfortunately the tummy fat (also hips and thighs) is the last to go because its the 1st to be put on. Just keep working them and eventually the fat will melt away and you'll be left with great abs.
I am the same way, its my belly, hip and thigh fat that is left. I can definately see my upper abs getting lines down each side from doing abs almost every day. Someday when this fat is completely gone, mabye I will see the lower abs.
In the meantime,
Alternate lower and upper crunches (with your knees bent) and after you do that hold 3 upper and lower crunches for about 3 counts. Also try this with one foot over the other and one knee over the other. This actuallly works the lower side abdominals. There are 6 mucles I believe in your abs. So you have to work all of them.
Hope this helps. If I didn't make sense, let me know and I will try to explain better.