I wouldn't say anything to the mom.
Next time the girl came over, I would tell her she's not allowed to play with the scooter because she didn't put it away nicely when asked AND she stuck her tongue out at me on top of it. I would tell her that if she can't play nicely and put things away when it's time, she can just go right back home.
One of two things will happen:
She will play nicely and do what you say so that she can continue to play at your house, OR she will run to her mom and tell her that you are mean, in which case another two things may happen.
Her mom will call you about being mean to her kid and you can explain about the disrespect....
OR the girl just won't come back anymore.
It was rare, but I had a few kids who told me they were going to tell on me to their moms and I just said, "Fine. Don't come back here without your mom".
The truly naughty ones didn't come back because they didn't want me telling their mom what they did. The other kids came back and we worked it out and had no further problems.
Kids didn't mess with me at my house.
I was strict, but strangely, I always had a bunch of kids flocking around.
Except for the ones who didn't want to play nicely or put toys away or share and get along.
There's no need for conflict. The girl's mother wasn't there. You were. Your house. If she comes back...deal with it.
You are not harming a child by saying that you will not accept certain behavior at your house. Why make her mom tell her that?
It's okay for you to say it.
Just my opinion.
No offense.
Best wishes.