Mariota obtained a BSc from the London School of Economics. She qualified in 1980. She was previously a partner with Cameron Markby and joined Payne Hicks Beach as a partner in 1989.

Mariota specialises in wills, trusts and general tax planning. She also deals with probates, including deeds of variation. She advises on charitable trust law. She specialises in advising elderly clients, including on the preparation of enduring powers of attorney and Public Guardianship matters.