My Mother is 70 . I am a perrmanent resisdent of the U.S and am wondering whether it is feasable for her to live here legally.

I would see an attorney about this. I can see why you want her with you, but health care would be a huge issue. It would, I think, depend on the pension in the UK as to whether she'd lose that. But health care, if she doesn't qualify for Medicare, could be very expensive, here. That doesn't mean impossible, but you really should see an elder attorney, preferable one who knows international issues. You may need two - one here and one in the UK. Good luck to you. Also, you should maybe check with major US health insurance companies about options for health care. You could try AARP, Blue Cross, Medica and others.
Carol