Nap times

Okay so I feel like such a lost cause with naps. My daughter is 8 months old. And she usually takes 3 naps and sometimes 4 depending on the day. She does not and has not ever napped well but she sleeps all night long. She generally takes about a 45 min nap at the most. She usually naps around 9am, 12:30ish, and the last one in between 3 -4. I'm trying so hard to get it down to 2 naps hoping she would nap longer but she is not having it. I'm at a loss and don't know what to do. She gets so crabby when I try to keep her awake longer that it's just a screaming fest and I end up putting her to bed.