You can give up to $15,000 ($30,000 if giving jointly) to each child without any reporting. Gifts great than that require you to file form 709 which is filed separately from your 1040 return.
You don't report gifts given or received on your tax return. Only gifts to IRS qualified charities. If you give one person 15,000 or more you need to file a separate 709 Gift Tax return, but there won't be any tax due on it.
GIFTS
Money that you receive as a gift is not taxable income to you, and you do not need to report it on your income tax return. Money that you gave as a gift to someone else is not deductible for your taxes.
Turbo Tax does not support the gift tax form 709, but here is a link:
https://www.irs.gov/pub/irs-pdf/f709.pdf
https://turbotax.intuit.com/tax-tips/estates/the-gift-tax-made-simple/L5tGWVC8N