My daughter would definitely try to block...
Well, I'm in Houston for a long weekend to visit my daughter. We played on Friday morning and near the end of the game, she made this play (she had to ask me to confirm that all of the CCCF tiles were already played):

The pumpkins were not from @DrMeeple's cool-looking
Halloween on Carcassonne expansion--we were playing our latest favorite rules combination: base game tiles plus
Das Gift, as well as
Balloons and
Gates & Walls. The smiling pumpkin next to her gray meeple is a "good Gift" that converts the meeple to a Large meeple. So, she trapped two of my meeples vs. one of her own, and she got all 5 points for the larger incomplete city. (This seemed extra cruel because the same tile would have allowed me to reinvade the city and share all the points.

)
As an aside, we included my wife in the game yesterday with the same tiles and expansions--here is the end-of-game photo:
