Meat bowl used for dairy

We have a set of ironstone bowls (link to product added if you need to see the material) that we use for meat. The night before we had served very hot chicken dish in them. The next day our babysitter erroneously used it to prepare oatmeal with milk in the microwave. No doubt that the milk was boiling in the bowl. She also used another bowl and I don’t know if it was used with meat, milk, or dairy.
Can these bowls be kashered? If so, what is the correct method
Also, we do not know which bowl was the one used for oatmeal and which was used for the unknown item as they have both been washed.

Thank you

I have viewed the photo you provided, in this case your bowl have a glass coating and therefore do not need to be kashered. You can only rely on this in an instance when one (dairy/meat) type was used in the dish of the other in error. You may still not use intentionally for both dairy and meat even when cold.