Maybe it's just a personal thing, but maybe don't hire nannies in the first place if you're paranoid about them becoming "more important" than you? Hypothetically, wouldn't it be better if your child has a bond with someone when you can't be around? You know, instead of repeatedly firing them so they only trust you whenever they see you? Again, hypothetically speaking.
As it happens, Mariah Carey - who has two-year-old twins - has her own view on the matter. She shared it during an interview with NYC's The Breakfast Club on Power 105.6 (which kind of explains the nightie)
"Unfortunately I have to have nannies but I'm very hands-on. I fire nannies like this and I hate doing it, but I have to because if they try to make themselves more important in the baby's mind than me..."
As a mother, you'll ultimately always be the most important one. Babbies need a bit of stability where possible. Most days, when collecting Lara from creche, I've to prise her away from one of the ladies because she doesn't want to leave. Do I take that personally? No. Not much. I cry a little internally, but sure needs must...