I wrote הילדה שותה and it says that it is almost correct. But it shows the same what I wrote. There is just "a" under Aleph. Does it require to write vowels? Or where is the problem?

The "typo" most are getting seems to be caused by the Niqqud, the often unwritten vowel system of Hebrew. I think that most mobile keyboards don't have it.

Does this mean that one is not a teetotaler like in English?

Technically the homophonous הילדה שוטה should be accepted as well. It means ‘the girl is a fool’, though.