Regarding the post by DairyIsClosed.
You don't need a trust lawyer.
What you do need to do is to name, within your will, who you wish to be the executor of the will. This would normally be your DH if he survives you.
You would also name a separate executor for if you died together, who could also be the trustee of your money if you die before child is 18. Executor(s) and trustee(s) - you can have multiple of each - can be same person/people, or different. They can be the Guardians, or someone else.
You should also, as a pp said, name beneficiaries in the instance of you all dying together, otherwise I think your parents would inherit. So maybe siblings, nieces/nephews, god-children, friends etc.
All this is fairly standard for a will and a good solicitor should only need to note your wishes for guardian, executor etc and then will word it appropriately.
It is unnecessary and costly to use a solicitor as executor, and usually slower than using a relative or friend.