She's Working Faster But Not Necessarily Better
The first time your maid comes to clean, she'll probably do a great job. This first cleaning will typically be more expensive than subsequent visits, too. The second and third visits establish the benchmarks for a standard cleaning. Pay attention to how long these visits take. If the second and third visits take three hours, then cleaning your home should consistently take about that long. If, after six months, you discover that the maid is in and out in two hours and 15 minutes, you have a problem. It could be that the maid is getting super-efficient, but it's more likely that she's cutting a few important corners but still charging you for the full treatment.