Let me work through this step-by-step.

Sally has 3 brothers.

Each of Sally's brothers has 2 sisters.

Since Sally is a girl, she is one of the sisters that each brother has.

If each brother has 2 sisters total, and Sally is one of them, then there must be 1 other sister besides Sally.

Therefore, Sally has 1 sister.

Sally has 2 sisters.

Here's the reasoning:

• Sally has 3 brothers.
• Each brother has 2 sisters.
• Since Sally is one of those sisters, the other sister is the other girl brothers share.

Therefore, Sally has 2 sisters in total.

Here are 5 jokes:

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

2. What do you call a bear with no teeth? A gummy bear!

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

4. What do you call a fake noodle? An impasta!

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

All 5 jokes are unique - each one has a different setup and punchline with no repeats.

Here are 5 jokes for you:

1. Why did the scarecrow win an award? Because he was outstanding in his field!
2. Why don't scientists trust atoms? Because they make up everything!
3. What do you call fake spaghetti? An impasta!
4. Why did the bicycle fall over? Because it was two-tired!
5. Why did the math book look sad? Because it had too many problems!

Number of unique jokes: 5