Please correct the sentences.

Hello,

      Is these sentences correct?

1. When she was pregnant for her first son, she smoked a lot so her first son was underweight when he was born.

2. What is the birth order of Jack to the Smith's?  Jack is the second child to the Smith's.

3.Vegetables can invigorate your immune system.

4.For how long after eating can we begin exercise?

Thank you very much.

Here are the correct sentences:

1. When she was pregnant with her first son, she smoked a lot  so her first son was underweight when he was born.

2. What is Jack's position in the birth order of the Smith children? Jack is the Smiths' second child.

3. Perfect!

4. How soon after eating can we begin exercise?

Thanks for your questions!

Amy