Comma

What did she want,  then? or What did she want then? 

Me too or me, too.

Do they need comma?

Thank you

Here are the basic rules for comma

The Comma (,)

The uses of the comma are:

1. Separate a list of items
   i.e.: Apples, pears, bananas and grapes are fruit
2. Indicates a word in apposition
   i.e.: The organisation, XYZ Enterprises, sends all members of staff on training at least once a year
3. Used before or after a participle phrasing
   i.e.: Being in possession of a lottery ticket, you may stand a chance to win
4. Indicate a slight pause
   i.e.: We have hardly had a summer in Gauteng, it has been overcast and rainy most days
5. Separate an exclamation or an expression
   i.e.: Oh dear, is that you meant?
6. Introduce direct speech
   i.e.: The speaker said, "The comma is used to introduce direct speech."
7. Ellipsis
   i.e.: Crips may be eaten too frequently; popcorn, too seldom
8. Used to indicate parenthesis*
   (whether it be related or non-related) i.e.: English Word Power, an interactive English language development software, helps to develop ones skills to effectively communicate in English.

Regarding your examples, none of them would require a comma.