Is she ready for cereal?

My almost 4 month old has been taking a big sleeping period of 5 hours at first, then goes to 4 hours for the rest of the night for over a month now (she eats every 3 hours or so during the day). She had a viral cold a few weeks ago, and every since then (she is over it now) she has been waking up every 3 hours at night again. Last night I tried to just give her a pacifier thinking that maybe she wasn't really hungry, but she was because I couldn't calm her any other way. Does this mean she is ready for cereal? (She has her 4month appoint. next week so I'll ask him then, but I wanted the opinion of some moms.)