I liked the idea of "porcelin tears" to portray her made-up face. You went through the process of covering up with make up quite well, showing what each part symbolised.
When you said in the fourth stanza that it's been going on for weeks, did you mean the feeling make up is a cover up or she's only been putting make up on for a few weeks?
It just seemed a little odd to say she's only been wearing make up for a matter of weeks...or was this just said to rhyme with "cheeks" - forced rhyme isn't good.
I've noticed a couple of times in here and in your poem "underneath her skin" (although I forgot to mention it in that comment,) that when you have conjunctions between words such as "is not" and "it is" you forget to add the apostrophe...just thought you may want to correct that.
Thanks for sharing.