Helen Cummings, who is eight months pregnant, had faced the possibility of life in prison without her children after admitting that she shot her husband, Tyler, in their home in Florida.
After flying back to Britain on Thursday, she described the moment when she was able to hold her 16-month-old son Terry in her arms again.
"It was just wonderful. He walked towards me with his arms up and I thought `This is great, he knows me'."
Mrs Cummings and her son were reunited in a Manchester hotel after she went to the city from Birmingham, where her flight from the United States touched down.
"When I was walking along the hallway towards the room I started to cry," Mrs Cummings said. "But I didn't want him to see me crying. Then I heard his voice and when I saw him I thought how much he'd grown up even though it's only been five weeks.
"It's such a relief to be back in Britain. The whole thing is such a tragedy. I've got to live with it for ever and I've got to tell the children about it."
A jury in Fort Lauderdale acquitted her of second-degree murder after hearing her husband had previously attacked her and that she feared for her life when she shot him after confronting him about pictures of him with another woman.
Mrs Cummings discovered that she was pregnant with her late husband's child during a routine medical examination while in jail awaiting trial.
If convicted she would have faced life in jail, without either of her children. "I tried not to think about that. I tried to hope for the best outcome but obviously that thought was very depressing," she said.
Mrs Cummings said of her experience: "It was the end of years and years of stress and torment but with a lot of happiness mixed in. It was a culmination of a lot of factors. The whole thing is a tragedy.
"I'm happy to be back with Terry, but I'm still sad of course. I do miss him [her late husband] and I still love him, but I can show that love by bringing up his children and by bringing them up the best I can."
Referring to the gun laws in America, Mrs Cummings said: "I don't think anybody should have guns. They're too powerful for ordinary people."
Mrs Cummings said she wanted to return to nursing when she was settled back in Britain, but would spend time with her family in her home town, Preston, Lancashire.
She would send photos and letters to her husband's family in America, but understood that they were still grieving.Reuse content