As your late wife left her share of your property to your children I am assuming you held the property as Tenants in common, if not I suggest you consider doing so, and leave your share of the property to your children. Remember if you were to be married in the future any existing will would be revoked unless you had clearly stated “ in contemplation of marriage”.
If your new wife is not financially dependent upon she should have no claim on your estate, but if you are contemplating marriage contact a local solicitor to prepare your will after explaining what you wish to achieve. The legal profession make a good deal of money from DIY wills so it could be money well spent.