Great job! She sounds just perfect! No, truly, LOTS OF SLEEP is good. This is when they do their growing. It is very important. Especially if you see signs in her that she gets overstimulated easy go with the nap. No need to keep a baby 8 weeks old awake if they are tired. They are still really newborns IMO.
I had a VERY sleepy baby. I STILL do. I worried constantly in the beginning about when she would be more awake, etc. but as she has gotten older the feedback I get is that this is BETTER than the reverse, and to just go with their needs.
Is the 9pm your last feed? Why do you want to change to 10?
At this age I found clustering in 2 hr intervals starting at 3pm to get a 9 hr stretch from my dd. So we did 3, 5, 7, 9 and then she would wake somewhere around 5-6 at this age. We also had a nap after the 3pm feed, sometimes going into th 7pm feed but usually VERY ready to go back to bed in the 9 o'clock hr. Make sense?
I have been told by countless docs re: my dd's sleep (because I usually bring it up every time I see a ped) that the only time I need to be concerned if she is listless and nonresponsive.
Hope this helps!