We have a family trust. Am I at liberty to make a small change by simply writing in the new info, date and initial it or must a lawyer do it?

The answer depends on what type of change it is, and the language of the trust.  If there is a provision in the  trust that specifically allows you to amend or revise it, you may be able to.  I would make a copy of the trust, write the change on that, and sign and date it with a notary or witness.  If the change is substantive (for example, omitting someone from the trust or changing distributions somehow, it 's probably worth paying a lawyer.