She knows, heck even the Swedish PM back in 1975 knew it (there's a TV clip of him laying it out).
Knowing what's best is way different from personal political goals though.
North/northwest Europe got pretty damn scared by the Chernobyl fallout (in practice many kinds of wild game was banned for sale for many years afterwards in some countries and we measured everything that could possibly be contaminated) and that scare runs deep for many still today.
(This is why you have the irony that the "green parties" in Europe are so damn anti-nuclear despite at least some of them realizing that you can't properly fight global warming without nuclear power)
She knows very well. However, there were protests against nuclear energy in Germany for quite some time. After the Fukushima incident they gained a lot more traction and pressure by the public and political opponents rose dramatically.
When the decision was put in place it was around 2011/12 iirc, back then the climate crisis debate was not nearly as big as it is today.
Also, burning coal is not the main target for the future of energy generation in Germany. The coal plants are just a side effect of the transition to a primarily renewable energy generation. Unfortunately due to coal energy companies having very close ties with the the ruling CDU Party, it's not surprising to see them get special treatment.
Knowing what's best is way different from personal political goals though.
North/northwest Europe got pretty damn scared by the Chernobyl fallout (in practice many kinds of wild game was banned for sale for many years afterwards in some countries and we measured everything that could possibly be contaminated) and that scare runs deep for many still today.
(This is why you have the irony that the "green parties" in Europe are so damn anti-nuclear despite at least some of them realizing that you can't properly fight global warming without nuclear power)