I'm not a nurse or a doctor so I'm obviously not an expert but from what I've read, iron in breastmilk is much more absorbable than iron from supplements so even though there's less in it, baby should be able to get most of her iron from breastmilk. Food is for fun until they're closer to one years old. That said, get her and yourself tested for iron levels and if you both look good it's probably fine. From what I've read, on the crunchier circles is that iron deficiencies in women are often a gut imbalance from too many iron-hungry bacteria types. So supplementing will often just feed the bacteria and not help iron levels. That's why a lot of anemic pregnant women see no improvement from iron supplementation in pills.
That, said grassfed
Grassfed liver is a wonderful first food for babies and it's full of iron, B-12, etc. My son likes to chew on big strips of it. He's 6 months but he refuses puree's.
The only supplement I give him is Cod liver oil and D drops. It might be surprising but he LOVES the cod liver oil. He slurps it up hungrily. I think babies intuitively eat what they need as long as we don't dement their taste buds with neolithic agents of disease.
I personally take a high quality prenatal, 6 carlson CLO capsules, 2 DHA carlson capsules, 100mg CoQ10, 180mcg K-2 mk-7, another 4000 Vitamin D-3, B complex, Magnesium, either a half an egg shell in a smoothie or a Calcium complex, and then I make sure I get all my other trace minerals like zinc from shellfish, bone-in sardines, liver, raw pastured egg yolks, and cruciferous veggies on a bi/tri-weekly basis. I also eat lots of red meat, sprinkle nutritional yeast on stuff, and try to listen to my body when it says to eat more veggies.
I feel confident I'm getting enough for junior and I when I eat this way. I don't know if you've done this already but the Westonaprice.org has tons of info on feeding mothers and babies.