A woman who threw a lit petrol bomb into a neighbour's garden while they were having a barbecue has been jailed after being told she could have killed someone.

A five-year-old boy had been with his parents and their friends enjoying a barbecue at the back of their home in Haslips Close, Norwich when "out of the blue" a petrol bomb was thrown into the garden by Josephine McAllister.

Norwich Crown Court heard the 30-year-old had been on a 36-hour drug and alcohol fuelled binge and was "off her face" when she lobbed the incendiary, landing just 30 centimetres away from the child.

McAllister appeared for sentence on Thursday (October 13) having previously admitted arson being reckless as to whether life was endangered following the incident on April 2 last year.

Judge Andrew Shaw had adjourned sentence from earlier in the week as he had "a great deal to think about".

He said it was "the hardest case I've ever had to sentence".

"On the one hand there's an extremely serious crime that clearly needs condign punishment and on the other hand there's a woman, now 30 who in the past 12 to 18 months or so has done everything she possibly can to try and turn her life around, so much so that two of her four children are now living with her again".

But in jailing a tearful McAllister for a total of three years and four months Judge Shaw said it was a case "where custody is unavoidable".

He said the offence was "all about risk" and insisted McAllister "had no idea where the lit petrol bomb would land".

He said if the petrol bomb had landed closer to or in the lit barbecue the affects of this "incredibly foolish act" could have been "tragic and quite likely fatal for someone".

Judge Shaw said "multiple people were endangered" and it was just "sheer fortune the ignited petrol didn't fall on the child or on the other five adults" at the barbecue who were left "terrified".

McAllister, of Horns Lane, Norwich, had earlier made a last-minute plea to the judge from the witness box, begging him to have mercy on her and not to send her to prison.

She said: "I just want to confirm how really sorry I am.

"I understand how serious this case is and how detestable it is."

McAllister added: "I feel so ashamed of my behaviour but I just wanted to beg for forgiveness and beg you not to remove me from my children."

She told the judge she was a "changed person" and promised she would "never go back" to being that person she was back in April last year.

An emotional McAllister said: "I hope you can have mercy on me".

The court had previously heard from John Morgans, prosecuting, how the lit bottle came "flying over the fence" with "flames coming out".

Those in the garden were described as being "terrified" with the victims unable to go back in the garden still as they fear "something like this will happen again".

Speaking after McAllister was sentenced, the mother of the boy who was almost hit by the petrol bomb, who did not want to be named, said: "I'm glad she's been put away".

The 35-year-old added: "I feel sorry for her children - it's not their fault, they had nothing to do with this. But she did that trying to harm someone.

"She knew there was people in the garden at the end of the day.

"She did what she did and has now got to face the consequences."

Andrew Oliver, mitigating, previously said McAllister had a "long history of drug and alcohol abuse".

He said the bottle had not been filled by her, although she threw the lit bottle.

Mr Oliver said she "suffered a paranoid and psychotic episode brought on by her drug abuse".

He added the fire was put out quickly and no-one was injured.