Normally we wait until around 8am as a courtesy because one of the regulars is on the west coast of Canada and the puzzles reset at midnight in each time zone.
But she'd posted that she'd already done us, so you were fine.
And yes Rubber Baby Buggy Bumpers is a common tongue twister/vocal exercise before performing - at least in North America it is. We used to say it before school concerts in warm up.
Just like Peter Piper, She Sells Seashells etc.