OK well. Honest it is. I read a lot of children's fiction regularly. So this is hopefully coming from an informed POV.
First of all well done for finishing a book and getting it out there for sale. That alone is a major achievement. So congratulations.
Now for the tough stuff. Hopefully this is helpful rather than critical.
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It is difficult to get the tone of a children's book right. It is easy to sound moralising, and/or condescending. Even though I only have the first chapter to work from I'm not sure you have avoided either. A specific example:
My mom and my dad each have a way of saying things that make me feel like they know everything and I should always try to listen to them.
I can just see the rolling of eyeballs now. All children should listen to their parents but they don't need to be told so in a book they are reading.
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Although you are writing as an adult with an adult perspective, you need to be realistic about the actions of a child. Any normal child could not be trusted not to sneak another cookie. It is the nature of children. We might want to believe that the lessons we impart work all the time, but I don't believe any normal child wouldn't take another one no matter how sick they got after over-indulging.
Sometimes my mom bakes dozens of cookies and leaves them just within my reach, but I never take them. I always ask and when I am allowed to have one, I only have one and I like it very much. Sometimes if you haven’t had something for a very long time, then the next time you do it is better than you remember and it makes you want to wait and wait and wait so it will be even better the next time.”
I'm also not convinced a 7 year old would still be having tea parties or allowing her Dad to bath her. They become quite self conscious around 7 -9 years old.
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Language. This is a tricky one. Good children's books are readable by any one. The only difference is that concepts are conveyed in a simpler fashion with fewer assumptions than in an adult book, otherwise you can write as for an adult but you need to keep the voice of the characters age appropriately realistic. For me personally I find the descriptions too simplistic while the 'voice' of the character is too adult but her actions are too young. It's hard to describe the feeling I get from reading.
I turn away and happily skip into the store
very young.
It is very scary for me when I can’t find you, and I’m sure it would have been very scary for you if you had gotten lost.
Very young. Condescending 'adult lecture' tone.
My mom smiles and says that she is happy I understand.
Too simplistic, condescending tone.
“It’s your genes.”
“Jeans?” he asks quite puzzled, “I’m not wearing jeans.”
I can’t help but giggle, “No, not those kinds of jeans, the genes that are inside you.”
“Oh, you mean like DNA.”
But then here the child is too adult. At 7 would they get the jeans/genes joke? Would they even be able to give this kind of response to an adult? In this tone? By contrast the adult is a bit stupid/young.
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There is a lot of indirect speech. I would use the first person and direct speech much more than you have. Indirect speech is very distancing for the reader. Younger readers in particular need to be drawn into the action. When some one says something, make them say it directly to the main character so that there is a feeling of direct and immediate action that draws the reader in.
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If I picked up this story in a store, I doubt I would have got past the first paragraph. The opening of the book should grab your attention and make you want to read it. If you picked this up in a store - would you want to read more? If you were 12 - 15 years would it grab your attention?
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Writing for kids is the hardest of all in my opinion. They are fussy readers, and it's hard to get the balance of simple enough to understand vs complex enough not to be condescending right. You have to make the content exciting and new enough to interest the child, while not entirely displeasing the adult paying for it.
The best advice I can give - is write a book you would like to read yourself - just a little simpler.
