"Seanmhair mhath agus màthair mhath."

Translation: A good grandmother and a good mother.

[Jean564934]

I'm not sure why it's mhath and not math in this sentence.

[Pete670519]

Because it's describing màthair and seanmhair here, which are both feminine nouns that don't begin with a vowel. So the adjective math lenites to mhath.

[DMcSea]

Whit's wrang wi' Granny & Mum?

[CIMacAonghais]

Did you try a good granny and a good mum?