Gifts that you make are never tax deductible. If you have rental income, you must pay tax on it. Whatever you do with the money afterward has no effect on the tax you pay.
If you gave the property to the children, then the rental income would be taxable income in the children‘s name. But there are significant legal and tax implications with this, and you should get competent, professional tax advice. I don’t think your friend is getting advice from the right people.
