I'm not an expert, but I feel that your daughter could be able to do it, and that she should learn. Perhaps she knows the answer but doesn't realise the concept of testing, as someone else has commented, ie she doesn't realise it's important for adults to hear that she can do something. If she's going to go to school and do exams, she will need to learn to give the correct answer when asked. This will do her incredibly well in school, or at least it seemed to help me (although I had to learn to hold back now and then to let others put their hands up).
At the mo I'm teaching my daughter to count which is why i thought I'd try and answer this. I don't know if this applies to you but I've been really afraid of telling my daughter that she's got the wrong answer, ie she's saying the wrong number. This has affected her learning to talk because I've been afraid to tell her her pronunciation is wrong, in case I offend her. However now I've realised this, things are improving.
I teach her to count as we walk up the stairs, with one number for each step. She keeps trying to start with 'two', so I have to say, 'No, one comes first!'. She sometimes tries to say 'two' twice. I have to say 'no, three comes next!' i try to be calm and gentle but firm, (basically not nasty or critical). Plain, simple instructions at her age.
But as your daughter's older maybe you'll have to explain why, eg. just say 'It's important that you learn to say these numbers in the right order'. Show her a computer keyboard, or a phone keypad - anything in real life that she needs to learn how to use, so she can understand why she needs to learn it. It also makes the learning multi sensory - the written out numbers provide a visual aid to her memory, and the real life object makes it more fun, a learning goal eg. learning to phone a family member, etc etc.
While you're teaching her, you may as well teach her to recognise the numbers in writing, even write them herself if she can hold a pen. You could make clear, bold flashcards (I think black and white is better for photographic memory and recognition than the modern vividly coloured stuff but you may disagree). There are some cbeebies programmes eg numberjacks but personally I find them a bit chaotic in terms of memory recall and visual stimulation but perhaps it's because I'm from an older generation!
My daughter has a good memory and I think what she's doing when she says the wrong number during our counting game is testing me. Perhaps she is wondering why things have to be in a certain order.
The concept of putting things in order is quite central to our british education system. I personally find that having an order helps me to remember things better as well, but I have a visual memory so a visual aid might help. Does your kiddie know the colours of the rainbow in order, or the letters of the alphabet? If not then these could be extension activities to dabble into that will set her up for school.
I hope this is helpful? xxx