Hi Naomi, I think your illustration is lovely and would be perfect on a greeting card. I like the soft colors and the loose drawing style. The only thing I think I would change a little bit is the composition by cropping a bit closer on the top and bottom. As it is right now, my eye is drawn away from the bird to the empty spaces in the background. Just my opinion...as I said, it's a lovely illustration!
I think iis is absolutely BEAUTIFUL!!! Such soft & beautiful colours that go really nice together I think!!!
I was confused at first as to what this yellow was till I realized the eggs indicated a bird, so I realized the bird was not an abstract fish. The white of the neck makes it look disconnected. Where is your light source? If it were me I would put in some more varying shadow over all and fade the yellow down the neck into white and then white back into yellow of the body. Light and shadow would give this more depth and brighten up this piace even more so. I love the scene you have created here, the wispy tree though I would give it more power by making it larger because she did chose this tree for her nest fill the upper part of the card and maybe even bring it down more on the side where the negitive space is. Print you out a copy and work on it then make changes to the piece IF you so choose to that way you won't mess up your orignal. IF you view your work in greyscale you will see there is not enough difference in tonal variation adding more lights and more darks of those color will help bring in balance.