Would this be a legal way of writing a living will?

Me and my husband want to write out a living will, we’re set to inherit his grandparents house and we have two children that we want raised by my brother and sister in law if something were to happen to us. I want to get a lawyer to write it for us but my husband is very cheap. He wants to just type it on the computer then have us both sign it in front of a notary. Would this be legal enough that my in-laws could not contest it?