My lawyer drafted my will.

Literal

Lawyer [subject-が] my will [obj-を] drafted.

遺言書 ('will, testament') is the specific word for a written last will — 遺言 ('dying words, will') + 書 ('document'). 作成する ('draft, create, produce') is the formal verb for producing documents — a common pairing with legal, bureaucratic, and formal outputs.