Isabelle "Izzy" Armstrong is the daughter of Owen Armstrong and currently a machinist at the Underworld sewing factory in Coronation Street, Weatherfield. Izzy was born with Ehlers-Danlos Syndrome and uses a wheelchair to get about.
In April 2010, Izzy met Kirk Sutherland online via a dating service and agreed to meet him at the Rovers. It was only when Izzy arrived at the pub that she realised that Kirk had used Jason Grimshaw's picture on his dating profile to attract interest. Izzy mouthed off at Kirk before leaving the pub. Despite this, she agreed to see him again on 7th May, whereupon she was no less prickly, snapping at David Platt and Graeme Proctor for spying on them and then bossing Kirk into applying for a job at Underworld. When Kirk failed the interview with factory boss Carla Connor, Izzy went to see Carla and challenged her assertion that Kirk couldn't do the job. Carla was impressed by Izzy's gall and after seeing that she was a skilled sewing machine user offered her the job. Izzy accepted and, upon reflection, Carla offered Kirk a job at the factory after all.
Izzy had a rocky relationship with her dad, Owen, as she thought he was too interfering. Izzy blamed him for the end of a promising relationship and afterwards refused to speak to him. On 9th June 2010, Owen tracked Izzy down to the Rovers but found her unwelcoming. He tried to make reparations by asking the landlady Liz McDonald to pass on a gift to Izzy. Izzy was annoyed at his underhanded method of getting to her but upon his arrival in the Rovers later that day agreed to talk to him, providing he accepted that her life was her own.
In November 2010, Izzy was shocked to discover that Gary has been injured in Afghanistan and one of his best friends Quinny had been killed. Gary returned home a few days later and Izzy stuck by his side. She became very concerned about Gary's aggressive behaviour and withdrawn manner as it was clear he was suffering from post-traumatic stress disorder.
In January 2011, she asked Owen to give Gary a job at the Builder's Yard. He complied with Izzy's request but Gary was accidentally locked in the van by Jason Grimshaw, Gary then got out and attacked Owen. Owen told Izzy that he wouldn't report him if she ended her relationship with him. Izzy was defiant and refused to break up with Gary, as it was clear he was still traumatised. In July 2011, Izzy was robbed by a gang of teenagers.
After learning of this Gary began to be over-protective of her and took away her wheelchair and refused to let her leave the house. When Katy and her boyfriend Chesney Brown turned up at the house asking to speak to Izzy, Gary told them that she was asleep, Katy spotted there was something wrong and told her father Owen about Gary acting strangely. Owen later went round to the house and knocked on the door but no one answered, so he kicked the door down and spotted Gary with Izzy in the corner crying, Gary later let Izzy go and went back to live with his mum, Anna for a few weeks.
After seeing how upset Gary was, she agreed to reconcile and in July 2012 she confided in good friend Fiz Stape that she was pregnant. Fiz suggested that Izzy told Gary which she duly did. Gary was excited about the pregnancy but fully aware of a number of health issues. Dr. Matt Carter told them that it was relatively risk-free and the Windass and Armstrong family celebrated the news. However, Izzy miscarried and realised that if she wanted children she would have to adopt. When Gary and Izzy discussed the probable adoption plans, they realised that Gary's criminal record and anger difficulties after Afghanistan would prevent this happening.
After long hard thought, they discovered that Izzy's sister Katy was willing to be a surrogate mum. Izzy and Gary agreed but called the whole thing off after remembering how ill Katy had been when pregnant with her own son, Joseph. After they overheard Izzy's dad Owen talking about Tina McIntyre not paying her rent and being in debt, they realised that Tina might be willing to be a surrogate for money, so they casually talked about it whilst Tina was serving them at the Rovers.
Tina offered to do it if the price was right, however partner Tommy Duckworth was very unhappy about the idea, however, Tina ignored him so he insisted she told Izzy and Gary that she had changed her mind otherwise he would leave her. Tina initially agreed but when Owen told them that he wanted the money back that he has already paid them and his flat, Tina went ahead with the implantation process. Much to Tommy's disappointment, Tina's pregnancy was confirmed two weeks later and it became public knowledge after she fainted in the street. Norris Cole overheard Gary saying that Tina was pregnant and everyone assumed she and Tommy were the parents but Tommy, struggling to cope with the situation, revealed the truth in the Rovers. Disgusted with Tommy's behaviour, Tina ended their relationship.
Izzy began to feel left out of the pregnancy when Gary and Tina went to birthing classes together. When Tina found out, she promised to involve her more. However, Gary became smitten with Tina and ended up making a pass at her, only to be rejected. Tina and Gary agreed to keep it a secret as they didn't want to upset Izzy, but she overheard them talking about it. As Izzy and Gary argued, Tina went into labour early and had their baby, who they named Jake. As the baby's life hung in the balance, Izzy refused to allow Gary near their son. When Tina realised how much they were arguing, she told them neither of them could see Jake until they sorted it out. Izzy and Gary agreed to stop arguing but were devastated when Tina told them she'd changed her mind and was keeping the baby. After visiting lawyers, they realised it would take years to get Jake back through the courts and Izzy gave up hope of keeping her son, telling Tina she can keep him. Realising she was wrong and that Jake belonged to Gary and Izzy, Tina gave him back. Shortly afterwards Izzy forgave Gary for making a pass at Tina and he moved back in with her and Jake.
- On her introduction to the programme, the character of Izzy was promoted as Coronation Street's first disabled regular , although Maud Grimes, who first appeared in 1993, also used a wheelchair.
- Izzy's surname was initially intended to be Butterfield, although by the transmission of her first episode it had been changed to Armstrong .