Wasn't bad?? Almost 12.5 hours sleep with no NW is fantastic!! Sounds like you have cracked it
As far as naptimes go, I think you can probably trust your instincts and put her down at 10am if you think that's the right time. Its pretty evident by the massive improvements you're seeing that M's problems were more about learning independent sleep skills than about routine.
As always, my only real advice is to be consistent. So if you're going to go by A times when working out naptimes and bedtimes then stick with that for a few days before being tempted to tweak.
As for the catnap - 45 mins max I would say. But really, what are the chances of her sleeping longer than that anyway?!!
Ollie was a pretty touchy baby (and is still a sensitive toddler!). I think your second baby has to be a lot more easy going cos you can't be as responsive to their needs as you were with the first. Sometimes we create more problems than we solve by trying so hard to do everything perfectly with our first child! It's just not possible with your second and you have to roll with the punches a little more - Amy mostly has 30-45 min naps, OT? UT? I don't know! It's virtually impossible to get her down for a nap at the right time cos there's so much else going on, I just have to do my best and not worry about it provided she's sleeping OK at night