The woman, 56, and the man, 28, were arrested at their home in the Hall Green area of Birmingham just before 6.30am yesterday.
They were taken to a police station in the West Midlands for questioning and bailed with instructions to return at a date in July.
The 93-year-old widow was attacked in her bed overnight between Monday 30 April and Tuesday 1 May.
A reward of up to £5,000 has been offered by the independent charity Crimestoppers for anyone who contacts them with information which leads to the arrest and conviction of Emma's attacker.
Detectives investigating the murder of an elderly grandmother in Birmingham are re-appealing for witnesses, three months after the attack.
Two people arrested following the assault of 94-year-old Emma Winnall have been released on bail.