Hello,
Take it from a mom who never sleeps...this too shall pass. Henry, my 5 month old, used to wake every two hours to eat but one day, out of the blue, he slept for 6 hours! It just so happened that he stayed up late (waiting for gramma to arrive); normally he went to bed around 6 or 7 but that night, he wasn't in his crib until 9...I was so amazed! So, I've been keeping him up later and he continues to sleep a long stretch and then a few shorter stretches (12-14 hours in all). Secondly, we tried feeding him cereal at that age and, he too, wanted nothing to do with it (isn't it hilarious though!!!). He now eats two solid food meals a day (banana cereal in the mornin and sweet potatoes at night) and LOVES it! Finally, Henry had the same 3 month growth spurt but he also had one at 4 months, too! (actually, considering he now weighs over 22 lbs...I don't think he's ever NOT been in a growht spurt :}...).
So, what I would suggest would be to
1. let her fuss for a few minutes,
2. try to soothe her without feeding her,
3. keep her up later,
4. feed her if she's hungry...it may just be another growth spurt
5. try the cereal agian in a few weeks...henry likes it with mashed banana :}, and
6. reassure yourself that, yes, one day, you will sleep again!
Hope this helps!
S.