The happy news has been confirmed by a rep for the actress.
'Mother, daddy, and baby are all doing great,' People quoted the rep, as saying.
The child was born on May 19.
After Nagra's pregnancy reports emerged, producers of the NBC medical drama decided to incorporate her pregnancy in some final episodes.
'We were trying to juggle how that was going to work because she [was] starting to show,' ER executive producer John Wells said at the time.
'What seemed sort of tragic at first ... when we talked about it ... there was a tremendous feeling of, ''Oh, there's this one [story] that we haven't done,'' so it's actually very exciting,' he had added.
Image: Keira Knightley poses with her Bend It Like Beckham co-star, Parminder at the 2004 Hollywood Awards in Beverly Hills.
Text: ANI | Photograph: Fred Prouser/Reuters