A member of attorney Maria C. Curtatone’s inner circle told The Somerville News that the former mayoral candidate is ready to formally announce her candidacy for the 2nd Middlesex District state senate seat left vacant by the passing of Charles E. Shannon Jr.

The source said Curtatone, sister to Mayor Joseph A. Curtatone, confirmed her decision at a courtesy visit Monday to the breakfast crowd at Union Square’s Sunny’s Deli.