Continuity mistake: When Paige follows Phoebe into the kitchen and is trying to convince her that she is telling the truth, Phoebe's right earring is missing in the shots showing both women, but it is there when the shot changes to close ups of Phoebe. It is an awfully large earring to be hidden by her hair in the two-shot. (00:25:20)
Continuity mistake: Paige's headstone reports her year of birth as 1975. But in episode 4-2: "Charmed Again, Part Two," Paige spoke with the nun to whom she was given as an infant on August 2, 1977, and Paige is always described as having been "given up at birth" by Patty and Sam. (00:27:15)
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.