Moves sealions out of the way.
So anyway, OP, as I said, I wouldn't eat anything prepared by a stranger in their own home, it's a perfectly standard reasonable hygiene concern and nothing to do with you personally. I wouldn't say a word, I just wouldn't eat it, and would try to stop my child from eating it.
But if they did, oh well, such is life, they used to eat dirt from time to time so they'll likely be fine.
However to be clear, this is not an uncommon boundary hygiene, it's very common indeed.
To return to your question however, I would not say it looked like showing off, and the sort of people who think that will be impossible to please anyway.
As you can see from this thread, a lot of women are just barking mad and desperate to have a go if they possibly can, they will pick any and no reason at all for starting a fight in an empty house.
You will find as you go through school there are a lot of deeply unpleasant people out there (and they're all on Mumsnet 😅)
I'd just buy something from a shop, but that's your choice obviously.
The thought behind it is kind.
There's not a single other word I need to write to clarify anything, and I have covered all the bases here so I will leave you to the barking sealions :)