As for Ffion, despite apparently already having fallen foul of the social networking site, she took to Facebook again after the party to declare that it had put the village where she lives "on the map".
Witnesses said it took police 40 minutes to calm the party down at the family home in Five Roads near Llanelli, Carmarthenshire, on Friday night.
One said: "There were about 200 people, with fights starting everywhere. It was chaos. I think someone threw a flatscreen telly out of the window. The house has been badly damaged."
In a series of internet posts after the party, Ffion wrote: "Five Roads is now on the map of madness :( urrrggg"
She commented that "everything kicked off" and she did not think she "should show my face in this village again!", adding that her birthday and Christmas had been ruined and that none of her family wanted to talk to her.
While she appeared to be at least somewhat repentant, friends complimented her on the party.
One wrote on her Facebook page: 'You had one hell of a party - many thanks, you deserve a pat on the back!!' while another added: 'It was brilliant while it lasted!'
After their lottery win seven years ago, Mrs Fosbrooke, then a supermarket cashier, and Mr Henry, a cleaner in a factory, went all over the world on exotic holidays, including a trip to Las Vegas.
The couple, who each had two children from previous relationships, with Ffion being the youngest, splashed out on property and cars as well as buying gifts for relatives.
They moved a few miles from their terrace house in a mining village and bought the most expensive house for miles around - a gated five-bedroom, six-bathroom mansion mockingly called Buckingham Palace by locals.
When they broke up earlier this year, dividing their fortune, Mrs Fosbrooke moved into a luxury property round the corner, which is where Friday's party was held.
A police spokesman said: "Police attended a property in the Five Roads area of Llanelli following reports of a disturbance.
"The call was received at approximately 9.20pm on Friday November 16. Six people were arrested for public order offences, criminal damage and possession of cannabis."
It is the latest in a string of UK teenagers' parties to be gatecrashed after details are posted online. Earlier this month, a court heard how a 13-year-old girl's birthday party was stormed by 60 older teenagers who had seen details on Facebook.
The girl's father, architect Shaun Beverley, tried to get the uninvited mob to leave his award-winning £1.1million home in Lytham St Annes, Lancashire, in July but was punched to the floor, kicked and spat on in a "vicious and horrendous" attack.
- DAILY MAIL