"no one but you notices"

[Odessa Dawn]

With its mix of satirical advice about “How to survive babies, and what they grow into: children” and laugh out loud humour, Sh*tty Mum is “about short cuts and parenting with 40 per cent effort” and “doing a half-assed job, but doing it well enough so that no one but you notices”.
More: How not to be the perfect mother

What does the word notices refer to?

[JMurray]

No one but you notices (is aware) that you are not making a 100% effort.

not a teacher

[Rover_KE]

'...nobody except you is aware that...'