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. 我不知道你这么在乎。
I like him but not that much. 我喜欢他，但 还不至于到那种程度。
Compare with "this": ad. (informal) so; to this degree
You can't have this much for breakfast. 早餐你不能吃这么多。
I've never been out this late before. 我从未在外面待得这么晚。
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.