hi girls,
firstly, jordieC - don't listen to those idiots that tell you you're child 'should' be doing this or that, every child has their own learning patterns, and when you're DD is ready, she will stop having the 3rd nap. As for swimming lessons, GO FOR IT, they will most likely tire her out so she will be more than happy to sleep as soon as you get home... and probably for a bit longer than usual too so you'll get a break as well!
i know i dont have as much experience as you girls but being around so many friends with children has helped me so much with deciding how to bring up my own.

DS is only 9 weeks old but i never forced him into any routine, he has made up his own, he will wake up around 6am, feed and go back to sleep for a few hours, then he might be awake for a couple of hours and drop off on his own a few times during the afternoon, and decided he wants to go to bed at 8pm every night...

as for bedtime routines when you're out... if i'm over someone's house with DS, i dont go home when he's ready for bed, if he wants to sleep, i give him a feed and put him in one of their beds until i'm ready to go... and because i've done that from when he was only a couple of weeks old, now he knows that bedtime is bedtime no matter where he is, he sleeps fine anywhere now, its great!

so after all that, in answer to you're question jordieC, you're little cherub is doing mighty fine just the way she is, she'll change when she's ready, going with the flow is the easiest thing to do for you and bubs, and i repeat dont listen to those "OH SHE'S STILL SLEEPING THAT MUCH??" people! every child is different, otherwise we'd all be clones...