I read the comments our fellow poet's have given. Most of them find the tone or mood of the poem a bit hilarious, and I agree it is because of your writing technique; the way you played with words. I mean How uniquely you wrote this poem which when we read might sounds to us hilarious, but from poet point of view I think the tone of this poem is nervousness, worrying about the things going to happen.
Even if it's for just one day, it is scaring the poet.
And this thing has happened in her life before as she mentioned, "But I will always fail the test."
Maybe that's the reason every time her mother in law visits it's a trial for her.
Because she never been able to please her or her mother in law does not like her because she stole piece of their heart(son).
How it has become poet's mother in law mission to find worse in everything good she does to please her.
Like find speck of dust, criticizing her about an already broken cup.
Ignoring that how hard the poet is trying to look the house neat and clean.
How much time she is giving of her life to turn a house into a home, and besides all that not seeing how happy her son is in the company of the his beloved wife(the poet).
But every time mother in law arrives only see flaws to prove the poet wrong.
on the other side, the poet always welcome her mother in law with a smile, with respect, even if she is scared, knowing that she is going to be a faulty wife one more time.
What I love about this poem is that the poet hasn't given up yet, and has no intention to give up in the future until she proves to her mother in law that his son made the right choice, not the fault choice.
So I find the tone of the poem optimistic too.
Milly, the rhyming scheme of your poems is always smooth. It is abab this time.
I don't know you noticed it or not but the scheme broke in 5th stanza with Aa part because of the words mission and fault.
The words choice like sneaky crook, and girlie hook are addition to this poem.
They sound good to read as they aren't clichés.
And one more thing, I did not mention anything about the subject or theme of the poem as I did not want to scare you anymore.
Without a doubt, it is a well deserved win.
It Cleary shows how honest you are in your efforts to please your mother in law.
And not only me, but judges agree on that too.
At last, I just want to congratulate you.
An honest write.