My 4-month old sleeps at 10pm and wakes up at 7am. Is 9 hours of sleep enough for her age?

When my son was about 3+/4 months, he's sleeping pattern was also similar's to Jamie's daughter and I got to catch up with my very much needed sleep. Once in a while he would wake up for feeding but otherwise he would wake up for the day when I am up for the day at about 6am. What I would say is, enjoy your sleeping for now! Babies are smart little beings and would cry to get attention if he"s hungry.