My cat had seven beautiful kittens 2 days ago no problems. She seems fine but I just felt her stomach and it feels like there is a kitten in there still, she even kind of winced the second time I felt it a little harder. Is there something I can give her to abort it or what do I do and could it be a placenta but feels pokey like bones?

It could be her ribs that you feel which would have opened up to accommodate all those kittens. If she is comfortable (not pacing), is nursing the kittens and licking them, I would guess she's okay, and there's no unborn kitten. If she seems distressed into tomorrow, you will have to scoop up the entire family and take them to a vet to have her be checked.

The uterus will shrink and feel quite firm, often like a remaining kitten... If you are indeed feeling the uterus.
Best thing to be certain there is no kitten left is an x-ray, or some other sort of imaging. A remaining kitten would probably be dead... may even be the reason it was there... a dead fetus is often difficult to deliver and would need to be removed for the cat's sake.
Questions like this are usually not a problem, but there is always a chance. As Wondergirl says, she is probably OK, but keep an eye on her. Look for an increase in her discharge, an unpleasant odor, an increase in disinterest in her newborns, for example. It may take a couple days for this to develop, so don't celebrate too soon.

If you do feel it necessary (for whatever reason) to take her to the vet, her babies should go with her, (again, as Wondergal said) just minimize any contact with the other cats and people in the clinic. Without her kittens she will be a little disagreeable to deal with.