Eat the kids for Christmas dinner. Don't sell the guns. HA! just kidding. Sell the guns of course. They're kids, they want to come downstairs on Christmas morning and open cool presents from santa.
I would say that as long as you aren't selling the last of your guns then yes i would sell them to get my wife and son gifts for xmas. But you need to keep enough to protect yourselves.
Always set aside ONE rifle, ONE pistol and ONE shotgun as your "line in the sand" and never sell those. Anything over that for me is "sale fodder" if I really need the money. Given the choice to work Overtime or come up with the cash someplace else however, that is usually my choice. And when we're fat with cash (not often) I buy extra guns with my wife's blessings. She's seen them save us more than once and in more ways than one.
I haven't had to sell guns or any of my stuff to pay for christmas bit if I had to I would. Guns come and go but my daughter and wife's happiness is way more important.