Well-wishers have flooded her room with flowers and cards to congratulate her on baby Liam Stephen, who is said to bear a close resemblance to his father.
The birth follows Mrs Blood's three-year battle to be allowed to have a child by her husband, Stephen. She and 30-year-old Stephen were planning to have children when he was struck down with meningitis and died in February 1995.
She persuaded doctors to remove sperm from his body while he was on a life-support machine, but, because it was taken without his consent, doctors could not legally release it from storage. The Human Fertilisation and Embryology Authority objected because Mrs Blood, who had been married for four years, did not have written consent from Mr Blood.
The Court of Appeal decided in February that she had the right to the sperm under European law and the Brussels Free University agreed to carry out insemination.
Professor Ian Cooke, consultant obstetrician and gynaecologist at Jessop Hospital, said baby Liam was being treated in the intensive care unit as he had breathing difficulties, but there was no major cause for concern. He expected Liam to be in the unit for another three to four days.
Mrs Blood was taken to the hospital at 11am on Friday when she began feeling discomfort and a decision was made to deliver the baby by caesarean section.
Mrs Blood's father, Mike McMahon, said that he was delighted at the birth and had had only two hours' sleep since.
"It is a pleasure to have reached this stage and I am very pleased to make this announcement," he said.
"It is the end of one part and a beginning of another as I am a grandad for the first time. I have asked Diane how she is and she's a little tired and a little sedated but elated is the best word to describe it."
Mr McMahon praised the support received by the family during the course of the legal campaign as well as his daughter's pregnancy.
Gill Blood, Stephen's mother, said: "I wish Stephen could have been here. It really is what he wanted." She said she felt "a mixture of emotions now but it is a relief to know that they are both okay and we have got our dream".Reuse content