Our girls beat the “unbeatables” by 2 runs at the end of the 10th inning, as was the customary inning for the score to be tallied in the books
I've never heard such a thing. Youth games usually have an inning or time limit, or both. What do you mean by "customary"?
In tournament play, which this was, the rules were to play 10 innings if tied in the 9th, which it was. They were only supposed to play a tenth inning to determine an outright winner. If they were tied at the end of the 10th, they were supposed to be co-winning teams. Those were the rules.
As far as never hearing of such a thing, you’re right. It happened as I’ve said nonetheless.
We all knew who won that game outright. The commissioner changed the rules so that the other team might have a chance at winning.
We were so proud of our girls. They were true champions that day, on and off the field.