I think it's a difficult one though if she's not telling the teachers that her mum did it.
At my dc's infant school they always used to have a craft competition at their summer fair. And I carefully let dd1 do her own thinking that was what was wanted. No. The first two years the four that won, there was absolutely no way the children had got anywhere near them.
So when she was year 2, I thought that I wasn't prepared to do it (and tbf I'm not artistic) but I worked out something stood out a little but was clearly done by a child.
She won the top prize.
So I used that technique with dd2 who started the following year. I didn't touch any part of it, but I told them what to do.
To my embarrassment dd2 won the top prize all three years (in year 2, I asked the head to make sure she didn't win, but apparently the outside judge insisted)
But that started a trend of more children doing it, because people noticed that the winner had done it herself so they decided the judging took that into consideration and so stepped back.
However when I was at infant school we had a decorated egg. I made the masterpiece of my life, which was a daffodil. Tbf it was very simple, and so it looked quite good. It was put on the table of those whose parents had done it. At that age I didn't take that as a compliment and I told the teacher and she believed me.
I also, when aged about 12yo, entered the village fair with a soft toy I'd made in for the children's competition. I did it all from designing the pattern, through to all the making and even managed a little parasol for it to hold (held together with bluetac!) When I went to pick the prize up, two ladies were saying very loudly that it was a crying shame that one had won because you could tell it was a kit.
So it can be hard for a teacher to know whether something has been done by an adult or a child, and, if they rely on the child telling them, then some children will lie, and some will have a great idea that they have done more than they have.
A young child might do a bit of colouring and say to the teacher that they did do it themselves, not realising how much work went into the rest.