Gloss over what Marie Curie's kids were (6,6)
I believe the answer is:
french polish
'gloss' is the definition.
(I've seen this before)
'over what marie curie's kids were' is the wordplay.
I cannot really see how this works, but
'over' could be 're' and 're' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for french polish that I've seen before include "rub - with 15a" , "Glossy varnish for wood" , "Marie Curie was" , "buff with this" , "Shine" .)