You didn’t say if the students (Ss) are different nationalities or not - if they are then she has lots of scope for getting them to talk about stereotypes, traditional dishes, customs, sports etc. Or she could put Ss of the same nationality into small groups or pairs to prepare a presentation to sell their country or capital city as a holiday / work destination to the other Ss who then vote on the best destination (actually she could still do that if the Ss are same nationality too but just ‘impose’ destinations of her choice).
Anything with an element of debate is good - get Ss to agree on ‘THe 3 Best’ and ‘The 3 Worst’ … things about their country, things about the host country, things about the Internet, films, books, the English language etc.
She could organise a ‘balloon debate’. Give 6 Ss a role - George Dubya Bush, Tom Cruise, Zinadine Zidane, Neslon Mandela, Aung San Suu Kyi, Catherine Zeta Jones, Bill Gates etc. They are in a hot air ballon but they are losing height so one person has to “leave” the balloon, each character gives reasons why they should be allowed to stay in, the ‘audience’ ask questions and vote, one person is thrown out and joins the audience, but guess what ? they are still losing height and so the process is repeated until there is one winner.
A bit more pedagogical is a grammar auction. The Ss are put into teams and ‘given’ a certain amount of money. Your girlfirend writes up sentences in English one by one and the Ss have to bet to buy the sentences, but only if the grammar is correct. If they buy an incorrect sentence they lose their money, if it is correct they still spend the money but win a point. The mistakes in some sentences should be fairly obscure to produce infighting within the teams
(NB she should only do this if she is confident that she will be able to explain why the ‘wrong’ sentences are wrong)
An important thing to realise is that even tho’ it is a conversation class, there’s nothing worng in having some sort of stimulus to get the conversation started - a short one paragraph story from an English language newspaper (synopsis of a film, reataurant review, cat stuck up a tree and rescued by fireman type story); play a song or musical extract and get the studenst to talk about it; show an extract from a film - the last few minutes and ask the Ss to reconstruct the events leading up to it, the opening scene and ask the Ss to predict how the story develops. Logic problmes are always good to - like “there’s a man in a diving suit in the middle of a burnt forest, how did he get there ?”
If I was her I’d write out a list of possible lessons and orgainse a programme to make sure I was mixing the more serious ones with more fun ones (and didn’t do three board games in a row for example). Good luck to you ‘Girlfriend of Jayrot’ and let us know how you get on. 