SO dd is 6 months old (today)!

We started oatmeal at 4 months and it was a disaster, so we waited again till 5 months and it was better, but she was still only eating small amounts, basically a tablespoon was her max.
Then we moved on to fruits and vegetables. Now she'll eat prunes and pears pretty well, but she can't STAND sweet potatoes. I'm getting a little worried because I'm thinking if she wont eat the sweetest of all the vegetables, how will she possibly want to eat any others? Did anyone elses DC hate sweet potatoes but do ok with other veggies?

We've gotten to the point where she'll usually gobble up the prunes and pears, but its inconsistent, is that normal at this age?

Also now she really isn't wanting the cereal anymore, like i said shes ok with the fruits but shuts her mouth for the oatmeal now too? I was getting concerned because I heard they needed the extra iron at 6 months, is that the same for her because she is formula fed or is that just a breast fed baby thing?

At my last appointment my ped said not to worry about it, but I was just curious if anyone had any experience? Thanks in advance