Hi all My daughter is nearly 16 weeks and im w...

Hi all My daughter is nearly 16 weeks and im wondering if i can start her on some rice cereal yet? I wanted to wait until she was closer to 6mths(like the experts say), but she seems to need more iron(i think). The reason i think this is because she cant stay awake much longer than an hour during the day and gets really whingy if she isnt put down for a sleep. I thought that at this age she would be able to stay up for at least 2 hours?