Apostrope use

[fannan]

Could you please confirm if the apostrophe is correctly used in the following examples. If it's not correctly used, why not? If it is correctly used, why is that so?

Jill’s shorter than Jan.
My name’s Jack.
My hair’s long and silky.

 

[ieltsonly]

Jill’s shorter than Jan.
My name’s Jack.
My hair’s long and silky.

All three are fine. The apostrophe indicates the contracted to be form.

Jill is shorter than Jan.
My name is Jack.
My hair is long and silky.

I hope this helps.
Stephen
ieltsonly.co.uk