ChasMom,
Sorry for the delay in replying, it's been a crazy week!
Well, I don't really know if I have mastered the nap extension thing, just yet. I was able to do it over the weekend, but as soon as she went back to the sitter, she started back with short naps. But, when I was able to extend, when she woke up babbling, I just left her in there. It took 15 minutes, but she eventually fell back asleep. I think if I could do that consistently for a week, she would probably quit waking up. Like I said, for the rest of the week at the sitters house, though, she has reverted back. So, I don't know if we have really made any progress. She is sleeping 12 hours at night though, so I count my blessings!
Good luck!