I suggest that you put her on leash and hook it to your belt. That way, you can keep an eye on her every move and see when she needs to "go."
You can also purchase something from the petstore that is supposed to attract the dog to the pad...it's a spray of some sort, that will make the pad more "interesting."
I would really suggest crate training. If you can't watch her, crate her. Take her out and as soon as you do, put her on the pad or take her downstairs and outside. If she doesn't "go" at that time, put her back in the crate and take her out again after 15 minutes. You may have to continue this cycle until she goes on the pad, but after a while she will catch on.
Make sure that as soon as she starts (not before and not after) going potty, you say "go potty!" This will become the command and she will start to go on cue, after a while.
Good luck, and here is my article about house training, including success tips:
LDT House Training