children does (sic)
When you see (sic) it means that something has been copied exactly even though it is a mistake. She should have said children do because 'children' is a plural subject.
into
Here into refers to something you are very interested in or like a lot.
Example: I'm really into learning English.
Click here for more idioms and common expressions.
'cause
Notice that the short form of because is spelled with an apostrophe - 'cause. Follow the link to find out more.
more information: 'cause
pretty much
just about; almost
Example: English is pretty much the hardest language to learn.
Click here for more idioms and common expressions.