Tamzine,
John Murnane was from the parish of Solohead, and as you stated was transported per 'Earl Grey' in 1836 with his brothers Michael and Thomas. John applied for his family to go out to Australia, however his wife Margaret was deceased by 1851. As you probably know his daughters Ellen and Mary arrived per 'St. Vincent' with Mary Murnane 'to look after the children'.
I would think that the baptismal record in the registers for Tipperary is for Margaret. The mother's name is incorrect - baptismal date 26 October 1835 - Margaret of John Murnane & Bridget Hogan - godparents Margaret Hogan (Sola). The girls stated on the manifest of the St Vincent that they were from Tipperary town and that their father was 'at Port Fairy'. This information is taken from 'Convict Applicatios to bring out families to Van Diemen's Land (allso NSW, Vic & WA) Indec 1827 - 1873 compiled by Coralie Mesecke.
With reference to the trial of John, Michael & Thomas Murnane, tried for breaking into and assaulting the house of William Day/Dee at Solohead; the Tipperary Free Press dated Wednesday 27 July 1836 carries an account. If you can't access this, let me know and I'll append it.
Regards,
Joan