@alextargetn to answer your specific question, the dependent should only be listed on ONE W-4 and best that the spouse with the highest income do that.
Also, it is best to complete the IRS Withholding Estimator tool so that the W-4s are completed correctly. It is otherwise somewhat 'messy' when there are two W-2s (either one person working two jobs or a married couple each working).
Have your most recent paystubs handy when completing this tool; it will tell you exactly how to complete each W-4.
https://www.irs.gov/individuals/tax-withholding-estimator
