My ds is the same. He's 5 weeks old now and I'm trying to get him onto a 3 hour routine (difficult because like your dd, his feeds are very random) but I never know if I should give him a pacifier for comfort or if he's genuinely hungry. And not to mention I'm always wondering if he's going through a growth spurt. He was born 3 weeks early so his adjusted age would be 2 wo... so I wonder if that plays into things too (??)