Answer:
The holiday party at the Smith's house was the most attended in the neighbourhood. It started at 7 o'clock, but we were running late. My mother's famous appetizers take time, and she wanted them to be perfect before she left. She's an amazing cook, but she was also a perfectionist. It wasn't the first time we were late to an event because my mother needed everything to be absolutely flawless.
Explanation:
Needs to be an apostrophe in the word "Smith's" because it is describing something that belongs to somebody. In the word "o'clock", there also needs to be an apostrophe, because it is a contraction of the word "of the clock". "Mother's" requires an apostrophe because it is describing something that belongs to her. (It is her famous appetizer). The next apostrophe is needed in the word "wasn't" because it is a combination of the words "was" and "not"