Rice cereal in bottle for 1 month old?

Basically my baby is always hungry and she's fed 5oz every 3-4 hours and she's 3 weeks and 5 days old. She always wants more it's awful. My mom told me earlier that she use to add plain rice cereal to me and my siblings bottles of milk as babies to make them thicker and it would fill us up more. She told me to try it, has anyone else tried and or do this?