I'm honestly a bit in shock... FOUR times a day for a 4-6 month old baby, *especially* a breastfed baby (breastmilk is such awesome nutrition) sounds like waaaay too much to me!!!
I agree w/ the other moms - at 4 months, a breastfed baby HAS NO NEED for solids *unless* they're showing developmental signs of readiness like sitting up *sturdily, all on their own* and being able to use their thumb + forefinger to pick small things up (called the "pincer grasp"), etc.:
http://kellymom.com/nutrition/solids/solids-when.html#dev...
Truthfully, if my ped told me to start feeding my breastfed 4-month-old rice cereal 4 times a day, I'd try not to look at him funny (breastmilk & formula have MORE nutrients than that cardboard-tasting rice cereal stuff!). And then I'd just nod and smile, go home, and NOT feed rice cereal to my baby at that age unless they were showing the signs of readiness discussed in the kellymom link above.
Shoot, why the rush to start solids? It only makes their poop turn from harmless breastfed baby poop to very stinky poop and can even constipate them, especially at that young age! Honestly, my opinion is to do your own research to see what other pediatricians say, and then do what YOU think is best for your daughter. Here's one well-respected pediatrician's opinion on starting solids - he's a very breastfeeding-friendly doc:
http://askdrsears.com/html/3/t032000.asp
Bottom line: Moms are the experts on their own babies, esp. when it comes to things like breastfeeding and solids (which MOST peds aren't even really trained on in med school, seriously!). If you think that much cereal sounds funny, trust your instincts and wait until you think you're daughter is showing you that she's ready.