VERY sleepy baby all of a sudden?

Carrie • Mama of 3

My 7 week old all of a sudden went from little cat naps all day long to long stretches of napping throughout the day and pretty good stretches of 3-4 hours at night too. She seems to only be awake for a feed and a change and that’s it. I know this is normal for a very young newborn but is this a sign of her being sick or anything now that she’s 7 weeks? She seems very happy but just sleepy. And of course the worrier in me assumes something is wrong!