Sally has one sister.

Reasoning

• Sally herself is a girl.
• She has 3 brothers.
• Each brother is said to have 2 sisters.
  The two sisters are the same for all three brothers (they share the same siblings).

Thus the total number of sisters in the family is 2. One of those sisters is Sally, leaving one other sister for her. So Sally has one sister.

I need to think through this step-by-step.

Given information:

• Sally is a girl
• Sally has 3 brothers
• Each brother has 2 sisters

Let me work out how many sisters are in the family total.

If each of Sally's 3 brothers has 2 sisters, and all the brothers are in the same family, then there must be 2 sisters total in the family.

Since Sally is one of those sisters, and there are 2 sisters total, Sally must have 1 sister.

Therefore, Sally has 1 sister.

Here are five jokes for you:

1. Why did the scarecrow win an award?
   Because he was outstanding in his field!

2. What do you call fake spaghetti?
   An impasta.

3. Why don’t scientists trust atoms?
   Because they make up everything.

4. How does a penguin build its house?
   Igloos it together.

5. What’s orange and sounds like a parrot?
   A carrot.

How many are unique?
All five jokes are distinct, so there are 5 unique jokes.

Here are 5 jokes for you:

1. Why don't scientists trust atoms? Because they make up everything!

2. I told my wife she was drawing her eyebrows too high. She looked surprised.

3. Why don't eggs tell jokes? They'd crack each other up!

4. I'm reading a book about anti-gravity. It's impossible to put down!

5. Why did the scarecrow win an award? He was outstanding in his field!

All 5 jokes are unique - each one has a different setup, punchline, and comedic concept. They cover different types of wordplay: scientific puns (#1, #4), visual humor (#2), food puns (#3), and agricultural wordplay (#5).