Use of parentheses to include both singular and/or plural possessive

GIVEN: "You can either pay for, or rent, your kid's baseball uniform."

QUESTION: If you are sending form letters to each of a number of parents, some of whom have 1 child, and others, 2 or more children, who will be playing ball, could you write:

EX.1. "You can either pay for, or rent, your kid's(s')baseball uniform(s)."

[I read the suggested "Questions that may already have your answer," above, which don't seem to pertain to the present query, and researched 's(s') online; and, so far, I haven't found anything on this. I compared my question to the questions and answers, here:
How do you make a word like "parent(s)" possessive? and thought that nothing there adequately answers it.]

UPDATE: @Davo's answer, below, is clearly a way to express what is intended. I'm asking whether or not the 's(s') construction would be correct/ understood.