As Toorak has indicated, if you leave a will, your children will
automatically be entitled to share a third of your 'moveable estate' (which is basically everything except your house, which is referred to as 'heritable property') if your husband is still alive when you die. If your husband dies before you do, that fraction is increased from one third to a half. It's the law in Scotland and there's absolutely nothing that you can do about it.
However the rules are different if you don't leave a will and, in your particular circumstances, it might actually be advantageous not to do so. If you die before your husband does, without leaving a will (i.e. 'intestate'), he will automatically get your share of the house as long as the value of that share doesn't exceed £473,000. He will will also automatically get the contents of the house (up to a maximum of £29,000) and a maximum of £50,000 in cash. If there's anything left after that, he will get a third of it, with your children sharing the other two-thirds.
https://www.thegazette.co.uk/wills-and-probate/content/103535
So, as long as you haven't got a house full of expensive stuff (with your share of it being valued at more than £29,000) and you don't leave more than £50,000 in the bank (or in the form of shares, etc), your husband will automatically get everything if you die intestate.
If you do decide to write a will though, make sure that it clearly states what should happen if your husband dies before you do.