If the Little Boom can articulate "It's stinky," it's time! The longer you wait, the harder it becomes (take it from somebody that knows... I had a girlfriend with a 5 year-old who thought "it isn't time yet"). My philosophy with my own kids is, if they can walk, they can shit in the commode. Sounds like the good lady has just volunteered for PLO (Permanent Latrine Orderly), or as we indelicately put it here, Shit Patrol!