No, mother is the main subject but it doesn't rename the subject, but "she" does rename "mother".
In other words, the answer is "she"
thanks
The word "mother" is a pronoun that renames the subject of this sentence. To determine this, first identify the subject of the sentence, which is "Your mother." In this case, "mother" is a noun. However, the sentence goes on to use a pronoun to refer back to the subject. The pronoun "she" is used to replace "Your mother" and therefore renames the subject.