Would claiming our child on my W-2 (only mine, not my husbands) change what we receive back in our tax return? Is there a way to tell how much? Thank you!

Well you would have less withholding taken out so you would probably get a smaller refund or even have a tax due.  No way to tell.

Look it up on the withholding charts starting on page 48 :  https://www.irs.gov/pub/irs-pdf/p15.pdf

You do not "claim" a child on a W-2.  You do fill out a W-4 at work and put down the number of allowances you want to claim so that the employer knows how much tax to withhold from your paychecks.  The more allowances you put down, the less the employer withholds.  If you have too little withheld, then you could wind up owing at tax time.  If you have more withheld than necessary, then your refund is more.  A big refund means you gave the government an interest free loan all year.

Try this tool:

https://www.irs.gov/individuals/tax-withholding-estimator