Is my 2 month old sleeping too much?

She goes to bed between 8 - 10 pm. She sleeps till about 3 am for feeding, diaper change, etc. Then goes back to sleep ~ 4-5 am till ~ 10 am. We go out for a walk or errand, then goes back to sleep ~ 12 pm and sleeps till 4 or 5 pm. I hate waking her when she sleeps so soundly. She's gaining weight fine and is generally a happy baby. Any advice on scheduling her?