"My happy mother is sweating."
Translation:Ñuha kirine muña nages.
Both should be correct, as far as I know. In High Valyrian, the adjective can stand in front or after the word it modifies. Sometimes, there's a difference in declension between the two forms, but it isn't the case here. There's also a difference in meaning - if the adjective follows the noun, it's emphasized and more official.