On Russian it translates the same "живут в Германии", but when you translate into English, there is some different. "are Living in Germany" - means that they live for the present moment, and "live in Germany" - means that they live there for long time. Well, in Russian we have only three times - Past, Present and Future
"Сёстры" is correct, but most of the time Russians don't write the letter "ё", substituting it with "е" because it's easier to write and to type ("ё" is placed on the same key as the "~" on the keyboard, most find it too far to reach). So it's written as "сестры" quite a lot, and it's not considered to be a mistake, but the "е" is supposed to represent "ё" in these cases and should be pronounces as such.
Here is the rule that covers most nouns:<pre>
feminine nouns ending in ь take -и. nouns ending in -ия, -ий or -ие also take -и (so that they end in -ии instead). all other nouns take -е</pre>