Nordquist, who is originally from Eagle River in Alaska and went to Northern State University in South Dakota, had moved to Unruly’s London office from New York.
She is now on trial for stalking, sending malicious communications and perverting course of justice at London’s Old Bailey court.
She denies the charges.
Prosecutor Claire Robinson said the pair embarked on an affair beginning in August last year but ‘wanted different things’ and broke up three months later.
After they separated Nordquist ‘seemed to want to get her ex-paramour’s attention, the court heard. ‘She left handwritten notes on his bike and desk. He thought that she was rather following him around the office and also that she continued to send him text messages.’
She then claimed she was eight weeks pregnant with his baby, jurors heard.
They went to the Royal London Hospital in Whitechapel and on 13 December Nordquist had an abortion.
Weeks said his ex-girlfriend got upset and ‘made a scene’ at the hospital.

Though the pair parted in November, when they returned to work after the Christmas break, Nordquist asked if they could rekindle their romance, the court heard.
Weeks spurned Nordquist’s request. She then sent him a message on Instagram saying: ‘I’m telling people at work I had an abortion and if they ask with who I’ll say you.’
Nordquist then posted an Instagram message saying she had an abortion after she ‘fell into a relationship’, said Robinson.
Nordquist allegedly posted a message, purporting to be from her friend, claiming she had taken an overdose on 5 January.
After Mr Weeks rang the police, Nordquist attempted to make it look like they were both being targeted by the same stalker, the court heard.
One email, which appeared to come from another person, read: ‘You are going to meet at 3pm at Shoreditch Grind (cafe).

‘If neither of you show, we’re going to release your past secrets around the office. We will come for you.’
When Weeks didn’t show he received a message saying: ‘I gave you both a chance to show up. Tick tock, the rabbit’s got f***ed.’
Robinson said: ‘The Crown suggest that these all came from Jessica Nordquist.’
She said the stalking campaign became ‘more and more sinister’.
Nordquist also sent tagged posts to Mr Weeks’ Unruly clients accusing him of rape, referencing his @weekmar page.
One, sent from an account called Karen Schuler said: ‘@weekmar raped her. Unruler raped and assaulted an employee. Still went to work with him and trying to cover it up.’
Nordquist attended Bethnal Green police station on 26 January and her phone and iPad were seized.
Police found searches about sending fake emails and stalking on her devices.
Ms Robinson said: ‘She told police she and Mark Weeks were being stalked. She claimed her searches were all related to trying to find out about stalking.’
When she was arrested again four days later, police found searches for ‘fake babies’ and a silicon baby bump had been ordered on Amazon.

Nordquist also sent tagged posts to Mr Weeks’ Unruly clients accusing him of rape, referencing his @weekmar page

She had also researched whether police can track where emails are sent from, the court heard.
The jury also heard Nordquist sent raunchy texts to Mr Weeks about her love life, claiming she had hooked up with a man called Max who she met in Soho.

Mr Weeks said he also received messages about a burglary at his home but he never replied.
‘I was under the impression it would be easy for Jess to find out if my house was burgled as my asking for a new laptop for example.’
He said while he was working from home a Reindeer, bought for him by workmates, as a Christmas gift went missing from his desk.
Weeks said emails about his private life were also sent to senior colleagues at Unruly.
‘I was embarrassed I was really anxious. The effect it was having on my career and my reputation in the company.
‘It was sent to the people who control how I progress within the company so obviously it was scary.
‘They were concerned about the content of the emails the day before so they wanted to make sure there were no security issues.
‘I had a toy reindeer on my desk at work which someone had given me for a Christmas. When I went back to the office that toy was no longer there.’

He said Nordquist alluded to chess in her emails and in one said: ‘If you can, protect the queen, she is the most valuable piece on the board she protects your king.’
Another message read: ‘The queen will have some words tomorrow. Did you not know she is worth 26 million dollars.’
Mr Weeks said his boss urged him to take two weeks off work on compassionate leave during the alleged stalking campaign.
He said he later received a message from his brother who lives in Jersey allegedly sent by Nordquist.
The message read: ‘Your brother is in trouble. You should be more careful.’
Mr Weeks added: ‘This was sent to my brother on Instagram. So the brother refereed to is me and he took the screen-grab and sent it to me.’
Weeks decided to remove himself from social media and deleted his Instagram account after forwarding many of the messages to the police.
Nordquist, of Tower Hamlets, east London, denies two counts stalking, two counts of sending malicious communications and one count of perverting course of justice. The trial continues.