S.,
3 months ago, I was right where you are. My little guy slept for basically the first 2 months of his life, then he "woke UP" and would not sleep during the day for 2 more months. It was hell, and I am pretty sure I put at least two posts on here about it. :) Of course, he would sleep in my arms like a champ, but the minute I put him down, he was up again. Aaaaahhhh!!! I even tried keeping her in my arms for 20-25 minutes until he seems "really" asleep and then putting him down - BING, eyes open. So frustrating. I also tried crying it out, which I am completely NOT opposed to (worked great with my first), but he would just cry and cry and cry and cry.
So.....another mom on here posted that she just finally realized that her baby needed to be held, and she joined Netflix and got used to it. As I didn't want to be holding my baby forever, I did a hybrid of this. When it was naptime, I always went through the exact same routine (nurse, rock, song) while watching a show I liked. Once he was done nursing, I'd burp him, then take him off to lay him down (awake). I would let him fuss/cry for as long as I could stand it (20-25 minutes). If he didn't fall asleep after that amount of time, I would get him up, change his diaper, let him play until the tired signs showed up again, then repeat the procedure. Sometimes, he'd nap. Sometimes, he wouldn't. On the days he wouldn't, he'd end up napping in my arms during a long show at the end of the afternoon (because I didn't want to hear him cry anymore). Eventually, the length of crying got less and less and the length/frequency of naps increased. Now, he's a great napper - he puts himself to sleep and takes 2-3 really good naps per day. So my advice is this: stick to your routine and don't stop doing it. Keep putting her down awake. Let her fuss/cry for as long as you can. It may seem like it's taking forever, but she will get used to the routine and will eventually become a good napper.
Best of luck to you!!
Amy K