Language Point 29

Sandy Finch, you're too young to wear that much makeup. (Para. 24)
Meaning: Sandy Finch, you're not old enough to wear so much makeup.
Notice that the mother greeted the daughter by full name, which means the mother was very firm in her opinion and/or wanted to be sure to get her daughter's full attention.
that: ad. (informal) so; to such a degree
I didn't know you cared that much. 我不知道你這么在乎。
I like him but not that much. 我喜歡他，但 還不至于到那種程度。
Compare with "this": ad. (informal) so; to this degree
You can't have this much for breakfast. 早餐你不能吃這么多。
I've never been out this late before. 我從未在外面待得這么晚。
Please notice that some people think it is not very good English to use "that" and "this" as adverbs; instead of "that late" or "this late", they say "as late as that" or "as late as this". In modern spoken English, however, use of "this" and "that" as adverbs is common and is considered more fluent.