Nap times?!

So I'm finding it really hard to get my little one to nap in the day. Have tried all sorts.

My 11 week old "should" be sleeping around 15 hours a day. She sleeps 6-7 hours over night. Then she has one 3 hour nap in the morning with me. And one more in her carrier for approx 2 hours. Then I can't seem to get her down again for more than 30 mins.

How are you ladies making up the hours!? Or do you not keep tabs on naps?

If she doesn't nap then she gets supppper cranky and fussy around 4ish.