Waking baby up

I know everyone says to wake them up after like what 3 hours or so.. But it's just so freaking annoying when she's sleeping and people are all 'oh how long has she been sleeping, if it's been more than 2 hours you should wake her.' 'Poor baby is probably starving and you're just letting her sleep' 'poor baby probably wants to eat' she's 9 days old , poops and pees the way she's supposed to do I know she's not over or under fed..