"I'm not very good at that"

[FrankiesKnuckle]

My daughter used to love all things arts and crafts, she'd spend ages colouring and sticking and painting. At pre school she was just starting to paint a defined version of our family - circles for heads, arms legs and big/small people. That was a few months ago. I hadn't really noticed that she's not been too interested in these things until a few days ago.
I'd asked her to help me make a card for a birthday, to draw in it. She said 'I can't draw very well, I'm not very good at it' she's 3yrs and 10 months old.
I've realised we've had no paintings or drawings home too.
I've always been super encouraging (something my parents were not)
And praised any piece of work she happily presented to me.
Do you think someone has said something to her? Or is she frustrated she thinks she can't do something?
It's quite upsetting to see her being despondent - she seemed genuinely sad when she said it!
Any thoughts much appreciated.

Mine all went through a phase of that in pre school. I wonder if it's because the standard of "art work" suddenly shoots so high that the nursery staff have to do most of the cutting out, sticking on, painting between the lines
I took to saying " not good enough yet " to mine and saying something about having fun trying anyway/ or practising lots.
My youngest now will attempt anything with gusto saying out loud to herself " I can't do it yet but I'll keep trying til i can"
Cute until she tries to fly

I did wonder if it's a 'thing'
I do try to explain about practice and learning but she's a bit, um, 'spirited'