Jellyfish

Statistics from the UK charity Carers Trust make for depressing reading, especially when it comes to the estimated 700,000 youngsters who are looking after someone at home. Of those, almost 70 per cent face bullying and only half have a specific person in the school who knows about their situation and helps them with it. All of which makes James Gardner's debut drama - co-written with Simon Lord - a timely reminder about these invisible children.

Sarah Taylor (Liv Hill) knows how to stand up to life and for herself - or at least she thinks she does. Quick with a foul-mouthed response in school, she tries to bring some sort of order to the chaos at home for her younger siblings (Jemima Newman and Henry Lile), taking the two of them to school in a carrier attached to the back of her bike and making sure they eat something, even if it's only boiled noodles or a packet of Space Invaders.

We quickly learn this is because their mum Karen (Sinead Matthews) has bipolar disorder - though its never stated outright - swinging between being unable to get out of bed and a manic phase that threatens to be even more damaging for her children. With her evenings spent cleaning at a beachfront amusement arcade, where men see her as ripe for sexual exploitation, Sarah's only outlet is a drama class, where she is being encouraged by the teacher (Cyril Nri) to express herself through stand-up.

As with a lot of debut films, there's an overstuffed feeling to this story. The stand-up idea initially feels fresh and though its punchline hits the mark, there isn't enough time for it to feel fully embedded within the rest of the plot. This is exacerbated by the fact that while Sarah's home feels like a living, breathing place and the seaside backdrop adds a faded economic realism, the school scenes are much stagier, possibly because we continually dip into the same class.

Other things niggle. When Sarah is watching Frankie Boyle to get a feel for stand-up, she laughs like a drain when he makes a joke about the Thundercats' Lion-O and Piers Morgan - hardly go-too subjects for the average modern teenager. The characters outside the family are also pushed to the brink of believability. Nri's teacher is almost a saint, while every other man in the film is a roaming predator.

But when Gardner puts Sarah in the family environment, he generates a jittery air of anxiety and uncertainty that offers us an emotional window into the teenager's life. Hill, who is only a couple of years older than her 15-year-old character, has a fierce screen presence, adeptly balancing Sarah's angry ballsiness and vulnerability. Her character's ability to 'cope' in certain sexually exploitative settings only makes her predicament all the more heartbreaking and Hill never falters whether its spitting abuse or showing us she's breaking on the inside. Matthews also gives a full-wattage performance, as Karen's moods blink on and off like a white hot bulb, ready to burn those around her. If Gardner and Lord's work still has room to grow, Hill already feels fully formed and ready to step into a lot more spotlights.