3 weeks old growth spurt?

Hey guys 😊 FTM here and i gotta say I love being a mommy. It can get hard at times but I have a really easy baby in my opinion. She sleeps a ton. Specifically as of today. Most of the time she’ll sleep 4 hours a time at night. My doctor said this is fine and to just feed her 3 oz in between rather than 2. So I feel blessed with that. And just now she slept 3 1/2 hours and woke up to feed, gave her 3 oz and she passes back out after a couple farts and a burp 😂 is this a growth spurt? I thought they were supposed to eat a bunch but she appears to just want to sleep. I know there’s a lot of development going on so I’m not going to wake her. I am formula feeding exclusively. I pumped and fed formula for a couple of weeks and now I’m only feeding formula. Is that also perhaps why she’s sleeping longer? TIA.

Here’s a couple pictures of my gorgeous girl. 🎀

From today 😂

The other day in her cute outfit.