Overnight fame has clearly not gone to her head. She may have just won rapturous applause from the nation's sports fans, the gender gratitude of 52 per cent of the population and the boyish admiration of the Prime Minister. But it is nearly the end of her lunch hour and she has her job to do.
Anyone who watched the women's World Cup cricket final last Sunday will recall Jo as the 22- year-old human dynamo who helped the England team to victory with her 38 runs, lively left-arm bowling and brilliant catches. She emerged as the undisputed 'Man of the Match'.
'It has all been fantastic,' says Jo, tapping buttons on the coffee machine by the side of her poster of the Chippendales. 'All the comments I've had about our win have been sheer admiration, how much people prefer to watch us to the men. They say our game is like cricket used to be when it was still interesting.'
In Jo's view, cricket fans have become disenchanted with the sterile predictability of the mainstream professional game: the ritual aggro of its helmeted, padded, visored, logo-decorated gladiators has destroyed all trace of the old elegance and technique. 'The men don't seem to enjoy playing as much as we do,' says Jo. 'As amateurs we were overjoyed at every wicket and the crowd could see it.'
It has not been easy for Jo to boldly go where few females have gone before. She is lucky to have a cricket-loving boss, who understands the need for time off. She has to travel to Bedford several times a week for training. With her every spare moment crammed with cricket, she cannot remember when she last had a proper holiday. It helps to have a fiercely loyal Mum (she still lives at home), two proud older sisters (one an ex-gynmast) and a protective, sporty boyfriend. 'He's incredibly supportive and follows me to all my matches even abroad. He's fabulous.' They plan to marry next spring.
The men in her life all seem to be shining towers of non-sexist strength. She is touchingly grateful to the male sports psychologist who has boosted her self-confidence over the last couple of years. But it is her father (now divorced and running a leather business in Hong Kong) who is her real hero.
'I was cricket mad ever since I would walk,' she recalls. 'I used to see my Dad playing for the Leicester Globetrotters. He cut down an adult-size bat for me to practise with while I was watching him.'
When she was older, the local boys would give her regular games in the park. Women's cricket is only rarely taught in schools. Spotting her precocious talent in the playground, however, the games master at her school obtained permission for her to play in the boys under- 11s. She spent her adolescence in her father's team and practising at the county ground. In 1985, a shrewd county coach invited her to join a local women's team.
This was just the springboard she needed. Her game has been improving ever since until now she is regularly described as a 'female Ian Botham'. But her childhood experiences of competing with all- male sides gave her a taste of what an aspiring woman cricketer could expect from the male chauvinist brigade. 'At school, a boy would get terrible stick if I bowled him out. The other team would look at me as if I had got two heads.'
Such playground attitudes don't evaporate magically in adult life, either. Since the World Cup tournament began in mid-July, sports commentators have enjoyed themselves hugely at the expense of women's cricket. While professing political correctness in one breath, these chaps have launched into a stream of schoolboy jokes in the next, revolving around the team's mini skirts, whether or not they wear boxes (no - not even an armoured bra), changing room arrangements and peeping toms (pure fantasy), where the girls polish the ball, and whether or not they are men in drag. One broadsheet wag even insisted that the girls wore a mysterious protective device called a 'manhole cover.'
What does Jo make of critics who insist that women simply cannot bowl properly over-arm? Who speculate on some physical impediment to this in the female physique? 'It's just unbelievable,' she fumes. 'You think, what does it take to convince them? Women invented over-arm bowling (a Victorian technique to cope with hooped skirts). The trouble is that so few men get to watch us play. What we lack in force we make up in style and skill. But as soon as they do see us they are converted.'
Press coverage changed its tone as the English team began winning matches. The sneering progressed rapidly via delighted surprise to outright euphoria as Jo made her final dramatic catch. MCC wrinklies rose to cheer and jubilant spectators invaded the pitch.
If there is any justice, the women's game will now attract some media respect and proper sponsorship. 'I daren't think how much of my money I've spent on cricket,' says Jo, recalling the expense of travelling, training and paying for her own kit. 'It's a real struggle.'
There is still the little matter of female membership of MCC and access to the sacred Long Room at Lord's (only another 20 years, soothes the MCC chairman). And what about those mini skirts? As she loads the last crankshaft into the back of the van, Jo explains that she prefers them to trousers, actually. As things stand, she'd rather her fellow players didn't resemble the men. Failure could be catching. With that, the doors slam and she drives away without looking back.