I have a 15 week old and use GF's rough nap schedule (actually her schedule for 8-12 week old babies, since that's what DD seems to need, plus a longer nap in the PM than GF recommends), since it works for DD, but don't use her feeding schedule. The two hour midday nap then co-incides with 22 month old DS's nap.
I swaddle her, and gently rock her in her crib to get her off. If she wakes, I go back in and shh her and rock her again, and that's usually enough to get her back to sleep. If not, white noise.
I'd LOVE her to take a dummy! Once DS stated taking a dummy (after I'd finally relented, having been extremely anti), sleep and naps were revolutionised. DD however, just won't take one.
But - swaddling and white noise seem to be working instead.
I'd also recommend doing the same thing each time you put her down, so that she starts to get the cues, and knows what's happening. Take her in, cuddle her, pull the curtains, lay her down, swaddle her - whatever you want to do - so that she knows it's nap time, and that she's safe. It just takes a bit of perseverance but is worth it, since enough day time sleep keeps them happy