Unless there are issues (as in poor weight gain or problems with supply) I would never wake a sleeping baby. In my opinion, if we needed an alarm clock to have our babies thrive, the human species would have long died out. I guess what I'm trying to say is: take your clues from her. She's obviously happy to sleep longer, so let her. She might cluster feed in the evenings or mornings to make up for it.
The only other reason for waking a sleeping baby would be to offer a roll-over feed. For example if you put her to sleep by 7pm and then go to bed by 10pm yourself and every night she wakes up at 11pm for a feed and ten sleeps through the rest of the night, it would make sense to wake her just before you go to bed to give her that feed in the hopes to maximise your own sleep time IYKWIM

Saša