"The mother is a woman."
Translation:Muña ābra issa.
What does the line above the a mean/sound like? And how about for other vowels?
The macron just shows that this is a long vowel. Every vowel in HV can be short or long. The long vowels are pronounced the same way as the short ones but just hold a bit longer.
For more information: https://wiki.dothraki.org/Learning_High_Valyrian#Grammar