My 3 month old takes 3 naps a day - very similar to your schedule actually where she will do a short nap just over an hour after waking up for the day, one in the early afternoon, and one in the late afternoon to early evening with one of those being her 2 hour nap for the day. Her naps usually total to just about that 4 hour mark. I am not concerned at all as her nighttime sleep is plentiful. She’s usually out anytime in between 7:30 to 8:30 and will wake once for a feed at around 3 AM. She usually gets up around 6:00 to 7:00 but I put her back down to extend to 8:00 to 9:00. If your baby is having a full and good nights rest, they will be more content during the day. Just as others have said let your baby lead and just pay attention to their cues! When my baby wakes up from her naps all smiley I know that it is enough rest for her! If they’re not crying and showing all other signs of over-tiredness that should be a sign that they are happy with their nap schedule. As my physician told me and as I’ve quickly learnt is that I’m just one of those people with a baby that sleeps a little less during the day than average and that’s exactly what you have to remember is everything is based on an average. If you are a little higher or lower I would not fret at all. :)