It's the equivalent of a question mark for a yes or no question

It's the question marker ma

I believe it's simply ending the sentence with a question that expects an answer. I could be mistaken.

他们 (Tāmen) = They

我们 (Wǒmen) = We

你们 (Nǐmen) = You (Plural)

们 (Men) is added to pluralize the nouns.

他 (Tā) = He

她 (Tā) = She

Same pronunciation but different character for male and female.

I also thought that I had it right. Then i just checked my screenshot and I realised I used, 他们 instead of 你们