Breast milk is obviously the best food for infants
however as stated in the International journal of analytical chemistry April 4th 2018

"Samples were collected from 42 nursery mothers with an average age of 28.3 ± 7.08 years delivered at full term (38–40 weeks) of gestation. All samples were obtained from nursery mothers' 3–520 lactation days postpartum during the hours of 08:00–11:30 a.m... (contained) concentrations of essential elements and heavy metals were as follows: sodium 330 ± 417 mg/L, magnesium 32.6 ± 15.5 mg/L, phosphorus 156 ± 46.2 mg/L, potassium 488 ± 146 mg/L, calcium 193 ± 53.2 mg/L, iron 1.65 ± 1.43 mg/L, copper 0.54 ± 0.46 mg/L, zinc 2.89 ± 3.23 mg/L, arsenic < 1 μg/L, and lead < 1 μg/L. Concentrations of heavy metals in maternal breast milk may have the important implication that it is not affected by environmental pollution in this province."

Most of these naturally occurring minerals are the self same trace element being over reacted too in this latest "moral panic" being used to sell newspapers, and click bait websites

Good for you! You are giving your baby a huge head start with your breast milk.

Scar mongering nonsense all most ALL food contains such heavy metals as Nickel, cadmium, mercury, zinc, arsenic,Chromium, sodium, potassium, uranium, copper and selenium . Organic brown rice, bananas, nuts (especially wall nuts and Brazil nut), and leafy green vegetables, fish (ALL FISH) even water contains trace amounts of these metals and ALWAYS HAS, in some cases lack of these minerals can cause ill health.
Only lead is a dangerous none naturally occurring contaminant found in foods, but the minuscule amounts entering the food chain are decreasing as the internal combustion engine both improves and is being phased out. You are more likely to get lead poisoning from living and breathing near a major road than through ingestion.
The key word is TRACE, in food sciences trace can mean as little as 1 part per Billion.

Soft smashed sweet potato (use pumped beast milk to make thinner if needed), smashed avocado, smashed banana, all ok around 6 months... add soft cooked fruits and veggies as tolerated over the next few months.

Good healthier, in Europe they did for first two years

That's good.

Shit is in everything processed .