“Aunty Caff,” said Emily firmly, as we shot through France on the Eurostar towards Disneyland Paris. “These characters. They are not real. There are people inside!”

Oh dear... Six-year-old Emily hadn’t even set foot inside the park, yet she was convinced that Mickey, Goofy and the gang — who tour the park posing for pictures and signing autographs — were fakes. It was akin to suggesting that Santa didn’t exist. I protested, but secretly worried — would our first aunt-niece trip together without her parents be a crushing disappointment?

Fortunately, the Disney magic kicked in as soon as we reached our twin room in the Disneyland Hotel, bang outside the park entrance. A spot of pretrip wand-waving had ensured that a candyfloss-pink Sleeping Beauty dress was draped across one of the beds. Hers, fortunately. It was not to come off for two days, and, after a pricey half-hour in one of the souvenir shops, was joined by tiara and pink cape, all worn over scruffy trainers.

Costume in place, Emily dragged me around the park. I gripped her hand until the poor girl’s circulation almost stopped. “Mummy and Daddy don’t hold my hand all the time,” she grumbled, as we charged up Main Street USA in the direction of Peter Pan’s Flight. This girl had done her homework.

And she loved this cute ride, which swirls you in a flying ship above a nighttime London landscape. We flew over Wendy, Tinkerbell, Peter Pan, and Captain Hook being menaced by the crocodile, while myriad tiny lights twinkled in the dark. Less enchanting to me — but another huge favourite with Emily — was It’s a Small World, in which we sailed through a multicoloured world of animatronic puppets dressed in national costumes, all dancing and kicking to a spectacularly irritating song.

But the highlight — which I loved too — was the new Buzz Lightyear Laser Blast. Our two-person teacup travelled through a land where Buzz’s enemies popped up at us from all angles. We shot them down with our laser guns, which looked suspiciously like hair-dryers. It got harder after Emily discovered the lever that whooshed our teacup round just as I was taking aim . . . it was brilliant fun.

The key to beating the queues is to use the Fastpass system — you obtain a Fastpass ticket for the most popular rides, then return at the stated time and bypass the queue — and to stay at one of the park hotels so you can visit in the evening. Over the 15 years of its operation, the park has become incredibly busy — visitor numbers are now 13 million a year, double those when it opened in 1992 — so planning is vital. Staying late is a great trick: Emily lasted until 10pm — there were no queues by then — before staggering back to the hotel to watch the 11pm firework display (oh, why so late?) from the club lounge.

This lounge — access to which comes with the Disneyland Hotel’s pricier rooms — is a lifesaver. On Sunday morning we had a relaxed breakfast here while, to Emily’s delight, characters including Goofy and Pinocchio came to our table, signed her book and posed for pictures. Service was prompt, the coffee and pastries delicious. But at the main restaurant on the floor below, I spotted a long queue for tables.

Emily had a very clear idea of which rides would suit her and which — such as the Big Thunder Mountain rollercoaster or the Pirates of the Caribbean ride — were too scary. I judged it wrong only once, when we took the Studio Tram Tour at the adjacent Walt Disney Studios, a smaller park themed around film-making. After ten minutes of rather dull trundling through film backlots, we were suddenly caught up in a shoot-out in Catastrophe Canyon: an oil tanker nearly fell on top of us, flames shot everywhere, gallons of water cascaded over the set. Poor Emily jumped into my arms in horror.

She soon recovered with a few turns on the gentle Flying Carpets over Agrabah ride. Then we headed, tiara now somewhat askew, for the train. “Aunty Caff,” said Emily. “These characters. There aren’t people inside, you know. They are really real.” Ah — that old Disney magic wins out again.

Need to know

Getting there: Cath and Emily Urquhart travelled with Rail Europe (0870 8304862, www.raileurope.co.uk), which has return fares on Eurostar from London to Marne La Vallée from £59 per adult and £44 per child.

Disneyland Resort Paris (0870 5030303, www.disneylandparis.com) offers a two-day package in May from £218 per adult and £59 per child (7-11). The price includes one night with breakfast at the Disneyland Hotel and two-day hopper tickets for the Disneyland Park and Walt Disney Studios Park. Throughout the 15th anniversary year (until March 2008), children under 7 visit free.

New this year: In Walt Disney Studios Park, two rides, based on Finding Nemo and Cars, will open on June 9: Crush’s Coaster is a trip under the ocean to explore a submarine wreck and meet three veggie sharks, while the Cars Race Rally lets younger kids board their favourite Cars character and whizz around the track. In the main park, the Once Upon a Dream parade has “smellyvision” — floats are fragranced with different scents.

Further information: www.disneylandparis.co.uk. A Brit’s Guide to Disneyland Resort Paris by Simon Veness (Foulsham, £8.99).