My DD is the same age and we've been getting EWs as well (though a little different, they used to be 6/6:15 and now it's more like 5:15/5:30). Like your LO she will play in her crib for a bit before we start our day. She used to sleep until 7 every morning, now she just won't go back to sleep. I have a few theories for us. One is she is waking up and then pooping when I feed her, which she has been doing since we started solids, so I think maybe the solids are waking her to poop and then after I change her she's wide awake. Still, occasionally she doesn't have to poop but we still have the same EW problem. My other theory is teething, which I remember with my other LOs they would often EW when teething. My DD just cut one tooth and has another coming, so that might be the problem. I am not sure if she is waking because she has to poop, or waking because of teeth and then is pooping, but either way I'm getting tired of it!
I do try to hold her off in the morning until her normal naptime, instead of letting it creep earlier. I know that makes for a really long A time, but it's the only way to keep her routine. She has been on 2 naps since 5 months though.
If you are trying to drop the catnap then I wouldn't be capping the morning nap. You could try stretching her A times to drop the third nap and see if that helps?