Помогите пожалуйста!

Ответ:

1) Nick's

2) sisters'

3) Smith's

4) woman's

5) women's

6) boys'

(Women's. Because 'women' is already plural, and is possessive. Ergo, you just add the apostrophe 's'. It would only be womens' if womens without the apostrophe was the plural of woman.)