Madeleine McCann's parents say the police investigation into their daughter's disappearance has encouraged them to believe she is still alive - as they also reveal they still buy her Christmas and birthday presents every year.
Speaking ahead of the 10th anniversary of her disappearance, her mother Kate McCann said: "It might not be as quick as we want, but there's real progress being made and I think we need to take heart from that.
"We just have to go with the process and follow it through - whatever it takes for as long as it takes. There is still hope that we can find Madeleine."
Last week, Scotland Yard said it had one "significant line of inquiry" to pursue which could solve the mystery of Madeleine's disappearance from the family's holiday apartment in Portugal on 3 May, 2007.
British and Portuguese police have failed so far to find any proof of Madeleine's fate, or any firm evidence to explain what might have happened to her.
Her father Gerry McCann, 48, said: "I think before Madeleine was taken, we felt we had managed to achieve our little perfect nuclear family of five.
"And we had that for a short period and I suppose, almost the same way as if your child becomes ill or seriously ill, or has died, like many other families have suffered... then your vision is altered and you have to adapt and you have a new normality. And unfortunately for us a new normality is a family of four."
Earlier this week, in a statement on the Find Madeleine appeal website, the couple said they were dreading the 10th anniversary, which they described as "a horrible marker of time, stolen time".
They said they were bracing themselves for the the media coverage which they believed would include "inaccuracies, half-truths and downright lies".
But they agreed to give one interview, to the BBC and the Press Association news agency.
Mr McCann, a heart consultant, defended the £11m spent so far on the Scotland Yard investigation.
He said: "I think some of that criticism is really quite unfair actually, because I know it's a single missing child, but there are millions of British tourists that go to the Algarve, year-on-year.
"And essentially you've got a British subject who was the subject of a crime and there were other crimes that came to light following Madeleine's abduction, that involved British tourists, so I think prosecuting it to a reasonable end is what you would expect."
Mrs McCann, 49, said: "You always do feel guilty as the parent of a missing child - that other families haven't had the publicity and the money, and I know there's reasons why that happened, but I guess the positive is that it has certainly brought the whole issue of missing children to the forefront and I think people have benefited in many different ways."
The couple also attacked the thousands of internet trolls who have criticised them over the years, largely for leaving their three children asleep while they dined with friends nearby that night.
Mrs McCann said: "I think it has been shocking... that aspect of human nature that I hadn't really encountered before.
"Because I think it's so far from how you would behave or people that you know would behave. It's been striking and quite hard really to get your head round. Because why would somebody write that? Why would somebody add to someone's upset - why would someone in a position of ignorance do something like that?"
They also confirmed they would be appealing against the latest judgement against them in an eight-year libel battle with former detective Goncalo Amaral.
He wrote a book in which he claimed Madeleine died accidentally in the apartment and they disposed of her body.
Mrs McCann, who had given up her job as a GP but is back working in the medical world, said she still bought Christmas and birthday presents for Madeleine to reflect her age.
She said: "I obviously have to think about what age she is and something that, whenever we find her, will still be appropriate, so a lot of thought goes into it.
"But I couldn't not, you know, she's still our daughter, she'll always be our daughter."
:: Watch the documentary Searching For Madeleine on Sky 1 on Tuesday, 2 May at 10pm, and on Sky News on Wednesday, 3 May at 8pm.