"Labhair do shinsir as Gaeilge."
Translation:Your ancestors spoke in Irish.
This means 'your ancestors spoke Irish (once/on one occasion)'. It should be 'Labhraíodh....' (past habitual).
Someone’s ancestors could well have only spoken Irish on one occasion; not everyone has ancestors from Ireland.
I just realized that Duolingo keeps telling me that I'm getting a typo on this word, because I've been paying too much attention to her pronunciation, and adding a fada to the first i in sinsir.