Maggie met Scott Lang, the man who would become her husband, and fell in love with him despite knowing his past criminal activities. Maggie supported her husband unconditionally until she became pregnant with their daughter Cassandra.
Maggie made Scott promise he would leave these activities behind, even though he claimed he was only stealing from crooks.
Scott Lang's Arrest
Maggie continued to support her husband Scott Lang when he was fired from Vistacorp for discovering they were illegally overcharging customers for their transactions. However, she tried to dissuade him from taking actions against them, knowing her husband was capable of manipulating the company's computers and steal from them in return.
Maggie reminded Scott his promise, and asked him to simply move on and find a new job and, especially, not do anything stupid. Scott did not heed his wife's advice, and ended being arrested for infiltrating both Vistacorp Headquarters and his former boss Geoff Zorick's mansion and stealing millions of dollars from the company, even though he returned it to its legitimate owners.
Maggie attended Scott's trial, crying as her husband was found guilty of his crimes and condemned to be incarcerated at San Quentin State Prison. Lang was arrested and given a three year sentence in San Quentin State Prison. Scott and Maggie divorced following Scott's incarceration, and Maggie eventually became engaged to Jim Paxton.
Unwelcome Family Reunion
On July 20, 2015, a recently released Scott Lang went to attend Cassie's birthday party uninvited which was held at Jim Paxton's house. This shocked Maggie and she almost choked on her drink when she was informed of Scott's arrival. Maggie took Scott outside to speak privately and discussed Scott's future with their family. Maggie stipulated that if Scott wanted to be involved in Cassie's life, he would need to stop stealing, find a stable job, and pay child support. Scott promised to improve his life and be there for Cassie.
The night after the party, Maggie tucked Cassie into her bed. Maggie asked if Cassie really liked the gift her father had given her; she assured her that she did because she liked its incredible ugliness. Cassie asked her mother if her father was a bad man because of the way she and Jim Paxton had spoken to him, but Maggie assured her that he was not, just complicated and easily confused.
Darren Cross Attacks
Scott Lang was later arrested for stealing from Hank Pym's home. Lang later escaped police custody using the Ant-Man Suit and Jim Paxton led the manhunt for him. During a family dinner with Maggie, Jim, and Cassie; Cassie expressed her support of her father evading the police.
Hank Pym had enlisted Scott Lang to become the new Ant-Man and steal the Yellowjacket Suit from Cross Technologies. Their attempted heist eventaully drew the ire of Darren Cross who put on the Yellowjacket suit and infiltrated Maggie Lang's home. Cross held Cassie Lang hostage in her bedroom, leaving Maggie to call the police. Maggie waited outside with the police as Ant-Man and Yellowjacket dueled in Cassie's bedroom while Jim Paxton charged into the house to protect and rescue Cassie. Ant-Man eventually defeated Yellowjacket and Cassie was rescued.
Months later, in gratitude for saving his family from Darren Cross, Paxton invited Scott Lang for a family breakfest at his home and informed him that he would not be going back to prison after escaping the last time. The dinner was cordial yet awkward.
To be added
- In the comics, Scott Lang's wife is named Margaret as well, but her nickname is "Peggy" rather than "Maggie". This comes possibly from the will to avoid confusion with Margaret "Peggy" Carter, who also appears in the movie.